ライフサイエンスコーパス: membered ring

1 and a linear topology via an unsaturated six-membered ring.

2 for selectivity toward the five- or the six-membered ring.

3 two naphthoquinone units connected by a five-membered ring.

4 fully substituted and highly oxygenated five-membered ring.

5 due to smaller hindrance for a five vs a six membered ring.

6 n/alkyl-Suzuki coupling used to close the 11-membered ring.

7 ctive exo-Diels-Alder reaction to form the 6-membered ring.

8 nar hexagonal B36 cluster with a central six-membered ring.

9 n mild activation sufficed to close the five membered ring.

10 Cgamma of the ligand giving a boat-like six-membered ring.

11 ient manner followed by cyclization of the 8-membered ring.

12 ing late-stage creation of the central seven-membered ring.

13 hietane is feasible, leaving intact the four-membered ring.

14 macrolactone, or direct cyclization to a 12-membered ring.

15 an imino-to-sulfur substitution in the five-membered ring.

16 assembly, also synthesizes the embedded four-membered ring.

17 thereby blocking cyclization to a third six-membered ring.

18 cyano functionalities to annulate a new five-membered ring.

19 new stereogenic center on the C2 of the five-membered ring.

20 with concomitant re-aromatization of the six-membered ring.

21 with fixed envelope conformation of the five-membered ring.

22 give rise to the desired N-heterocyclic four-membered ring.

23 oxamide oxygens within Mn-mu-S-CH(2) -C-O, 5-membered rings.

24 ed as benzenoids, consisting of only fused 6-membered rings.

25 d five-membered rings, in preference to four membered rings.

26 s are mainly described to give five- and six-membered rings.

27 ular cycloaddition reaction producing 5 to 7-membered rings.

28 their influence on the conformations of six-membered rings.

29 m ions have been imaged sitting inside the 7-membered rings.

30 charged core composed of a series of fused 6-membered rings.

31 hat the final structure consists of only six-membered rings.

32 dialene-like structures at the proximal five-membered rings.

33 oms bridged by carbene groups yielding seven-membered rings.

34 teristics, such as windows that comprise odd-membered rings.

35 o [6 + 4] cycloaddition to form unbridged 10-membered rings.

36 orward fashion, including six- through eight-membered rings.

37 2] manner to give rise to seven- and/or five-membered rings.

38 ular Diels-Alder (TADA) reactions with 10-18-membered rings.

39 nal diolefins when affording smaller than 12-membered rings.

40 aliphatic cyclic ethers with four- to seven-membered rings.

41 etic transformations for the assembly of six-membered rings.

42 h aryl and vinyl halides, and five- to seven-membered rings.

43 significant delocalization around the three-membered rings.

44 double bonds, leading to benzannulated four-membered rings.

45 d for the synthesis of highly strained, four-membered rings.

46 lable five-membered rings into strained four-membered rings.

47 isolated open nickel(II) sites in their six-membered rings.

48 (ABA) and ten (ANA) consecutively fused six-membered rings.

49 ms consisting of fused Huckel or Mobius four-membered rings.

50 nt simultaneous construction of the two five-membered rings.

51 o enables the synthesis of 3-, 5-, 6-, and 7-membered rings.

52 a transition states involving six- and seven-membered rings (1,5 and 1,6 H-shifts, respectively) of a

53 ved with the unbleachable analogue, 11-cis-6-membered ring (11-cis-6mr)-retinal, which has therapeuti

54 Ti sites are confined within the smaller 12-membered ring (12-MR) micropores of Ti-Beta.

55 of the nitrile imine into 4pi-electron three-membered-ring 3-methyl-1H-diazirine, which photorearrang

56 (2) structures incorporating seven- or eight-membered rings, (3) selective heteroatom doping, and (4)

57 Si:Al ratios, the volumetric density of six-membered-rings (6MR) containing two Al (2Al sites) is co

58 ction, known to occur predominantly in the 8-membered ring (8MR) pockets of MOR, is used as a site-sp

59 ane that consists of two triply entwined 114-membered rings, a molecular link.

60 arrangement of substituents on one of its 5-membered rings, a pattern shared by a number of other te

61 ysts are effective for the formation of five-membered rings, a ruthenium-based system that affords th

62 ]tetraphene, which "unexpectedly" forms five-membered rings accompanying highly selective 1,2-shift o

63 c acid (APCH), which is constrained by a six-membered ring across its Calpha-Cbeta bond.

64 spin trap, leading to the formation of a six-membered ring adduct, occurs through a very favorable pa

65 ck-Matsuda reaction of five-, six- and seven-membered ring alkenes and aryl diazonium salts is presen

66 ed radical-mediated ring contraction of five-membered-ring alkenyl boronate complexes into cyclobutan

67 y enantioselective addition to racemic seven-membered-ring allyl chlorides for the first time.

68 The scarcity of 8- to 12-membered rings among clinically approved drugs is indica

69 strates for FPP synthase, giving novel seven-membered ring analogues of GPP and FPP.

70 either two eight-membered rings or an eight-membered ring and an imidazolone ring are also detailed.

71 catalysed fragmentation to install the seven-membered ring and vicinal quaternary stereocentres of th

72 formal pentalene subunit at the central five-membered rings and [5]-radialene-like structures at the

73 rganic synthesis(2) for the formation of six-membered rings and are now well-established in biosynthe

74 ediated Yamamoto reaction to close the seven-membered rings and create the borepins 4a-c.

75 d N-heterocycles, comprised of six-and seven-membered rings and is of high significance in the contex

76 This versatile route converts five- to six-membered rings and provides a detailed view of high temp

77 can also be extended to the formation of six-membered rings and to N-homoallylindoles.

78 nt effects ring contraction to a strained 10-membered ring, and that strain in turn drives the Cope r

79 The reaction generates 5- to 9-membered rings, and of the 44 examples studied, 10 inclu

80 the approach by preparing recifeiolide (a 12-membered-ring antibiotic) and pacritinib (an 18-membered

81 nyl)thiophenes having five-, six-, and seven-membered rings are aromatized benzothiophene products, w

82 reactions, cycloadditions that generate five-membered rings are comparatively limited in scope.

83 The steric effects of substituents on five-membered rings are less pronounced than those on six-mem

84 rings are cis-fused and the five- and three-membered rings are mutually trans, provides a synthetic

85 Carbo- and heterocycles of five- and six-membered rings are obtained in good yields.

86 acene derivatives with externally fused five-membered rings are prepared by means of a key palladium-

87 Whereas six-membered rings are readily accessible from Diels-Alder r

88 hiophene products, whereas eight- and twelve-membered rings are un-rearranged adducts.

89 s the [4+2] Diels-Alder reaction to form six-membered rings, are among the most powerful and widely u

90 enes, which contain four linearly fused five-membered rings, are benchtop stable and behave as hole-t

91 th other electron-rich heteroaromatics and 6-membered ring aromatics provided they had donor groups i

92 the same pattern of cyclization provided six-membered rings as an illustration of the reactivity of a

93 nsists of two benzene rings joined by a four-membered ring at its core.

94 The chair preference of a seven-membered ring at the fluorine transfer transition state

95 These seven-membered-ring aza ketones are prepared in good yield wit

96 highly substituted nitrogen-containing seven-membered rings-azepanes.

97 Suitable substitution of the five-membered ring backbone exemplarily allowed the Co-cataly

98 rings are less pronounced than those on six-membered rings because of the difference in bond angles.

99 2)NH and R(2)NH(2)(+) groups on the same six-membered ring, behaving both as an electron donor and an

100 ort a photochemical strategy to obtain seven-membered ring benzosultams in one step, using saccharin

101 s showed that electron donation on the three-membered ring boosted the TOF of ring opening.

102 ed the ketone and dipolarophile to give five-membered rings but mixtures resulted with four atoms in

103 e conformational equilibria of the heterosix-membered ring by low temperature (13)C NMR spectroscopy

104 competition between the formation of a five-membered ring by ortho-attack at the armchair edge and f

105 at the armchair edge and formation of a six-membered ring by peri-attack at the zigzag edge clearly

106 -bisallylaldehydes rearrange to generate six-membered rings by a mechanism triggered by aldehyde C-H

107 e seven-membered ring hydrogen bond and five-membered ring C(4-5-10-13-14) cyclization, from which th

108 tures a type-I beta-turn with a canonical 10-membered ring C=O-H-N hydrogen bond between backbone ami

109 ion, only the formation of the strained four-membered ring can be achieved instead of the thermodynam

110 hromophores that are linked between two five-membered rings can access planarized structures with red

111 While formation of 5- and 6-membered rings can be achieved from the free alcohols us

112 The five-membered ring carbodiimide is a stable structure, possib

113 lmaleimide is isolated for the five- and six-membered ring cases.

114 iminium ion formation, and seven- and eight-membered ring catalysts are more active than smaller rin

115 e inorganic framework bearing the largest 18-membered-ring channels in gallium phosphites, denoted as

116 philic group affects the possibility of a 10-membered ring closure by the Nicholas reaction.

117 p was tethered to the acetal group by a five-membered ring compared to one where it was tethered by a

118 hey are mainly hexadecamers, with each eight-membered ring composed of one or two (in Archaea) or eig

119 The synthesis of a seven-membered ring compound containing a phenol ether moiety

120 studied, all efforts to synthesize the five-membered ring compound have thus far met with failure.

121 re close to 0 degrees , but in five- and six-membered ring compounds and in open-chain compounds the

122 rtion of the catalytic domain, such as a six-membered ring, confer selectivity for HKs.

123 a supported our hypothesis that the rigid 12-membered ring containing an alpha,beta-unsaturated carbo

124 n of the 13-membered ring to 14-,15-, and 16-membered rings containing beta(3)-homo amino acids with

125 ic acid led to jadomycin AVA, a second eight-membered ring-containing jadomycin.

126 ategy may potentially enable access to all 7-membered-ring-containing Lycopodium alkaloids and provid

127 chalcogens led to the conversion of the four-membered ring core, Ni(mu-E(PhX))(mu-S'(N2))Fe, to a fiv

128 e-pot sequence for constructing the common 7-membered-ring core system, followed by either a biomimet

129 Indoles with a deactivated five-membered ring could also take part in the reaction with

130 ween binuclear Cu(I) sites and N2O in the 10-membered rings Cu-ZSM-5.

131 is located in the intersection of the two 10 membered rings, Cu-MOR provides two distinct local struc

132 ion of a fused-ring benzazirine into a seven-membered ring cyclic ketenimine.

133 activation processes proceed through a five-membered-ring cyclometallated intermediate.

134 ters is described, proceeding through a four-membered-ring cyclopalladation pathway.

135 activation mode that proceeds through a four-membered-ring cyclopalladation pathway.

136 s (net-cBUs), 12-connected (12-c) double six-membered ring (d6R) building units.

137 the first time that RE-MOFs with double six-membered ring (d6R) secondary building units are isolate

138 tive nets with a vertex figure as double six-membered-ring (d6R) building unit, namely the (4,12)-coo

139 he cyclization delivered either five- or six-membered rings depending on the temperature of the exper

140 Distribution of produced five- or seven-membered rings depends on the substitution pattern on th

141 idine-2-caboxylic acid, a more flexible four-membered ring derivative of proline, shows relaxed eIF5A

142 it of the 3-sila-1,2,4-trioxepane yields six-membered ring diisopropylsilylene acetals.

143 ropionamide, reveals a common Li-N-Li-N four-membered-ring dimeric structure motif.

144 silanolate, allylic acetate precursors to 5-membered rings display distinct modes of activation.

145 migration processes are observed in the five-membered ring due to the high barrier to 1,3-hydrogen mi

146 ained amide, amine, and hetero-aromatic five-membered rings, each of which had a hetero-atom and an u

147 bered-ring antibiotic) and pacritinib (an 18-membered-ring enzyme inhibitor), the Z-isomer of which i

148 and oxygen medium rings, in particular nine-membered rings, epitomize a unique area of chemical spac

149 -position versus a topologically similar six-membered ring formation at the armchair edge reveals tha

150 hway proceeds via the initial step of a five-membered ring formation upon attack of the hydrazine, fo

151 attack at the zigzag edge clearly favors six-membered ring formation.

152 s proposed to account for the selective five-membered-ring formation with the rearrangement of the ar

153 and the systems with fused benzene and a six-membered ring formed atropisomers separated by a barrier

154 ples accounting for the preparation of eight-membered rings from bis(allenes) in the absence of metal

155 A concise synthesis of quinoline-fused eight-membered rings from simple starting materials is describ

156 ng molecules with substructures such as five-membered rings from training spaces nevertheless produce

157 rentiating among these isomers in their five-membered ring furanose structure and smaller energetic d

158 tenolide to produce stereoselectively a five-membered ring fused bicyclic lactone, the core structure

159 ionenes (spiro-ionenes) containing 5- and 6-membered rings fused by central nitrogen cations.

160 2] cycloaddition of the formed six- or seven-membered ring-fused cyclopentadiene system, and a final

161 )Si(II)]Ge(I)}(2)Ni(II) complex with a three-membered ring Ge(2)Ni-metallacycle was obtained via redu

162 ty is strongly ring size dependent, with six-membered rings giving exclusively alpha-benzyl pentenoli

163 carried out to form seven-membered and eight-membered rings, giving rise to tetranitro dipyrazolo-1,3

164 rivatives (containing five-, six-, and seven-membered rings) have been investigated.

165 We report that the silylation of five-membered-ring heteroarenes occurs with high sterically d

166 dular access to a diverse collection of nine-membered ring heterocycles in a one-pot cascade and with

167 ne have shown reliable selectivity with five-membered-ring heterocycles.

168 ontribution adds novel PMPs containing eight-membered rings, highlights the effects these derivatizat

169 doubly locked configuration, i.e., the seven-membered ring hydrogen bond and five-membered ring C(4-5

170 es revealed that the syn isomer favors a six-membered ring hydrogen bond to nitrogen and the anti iso

171 o nitrogen and the anti isomer favors a five-membered ring hydrogen bond to oxygen.

172 f each Gln sidechain participates in a seven-membered ring hydrogen bond with the backbone NH of the

173 trialkoxyphenyl-substituted alkynes into six-membered rings, i.e., tetrahydropyridines, was developed

174 ent a facile synthesis of a substituted five-membered ring in flames and stellar outflows.

175 mediate to form an energetically stable four-membered ring in the singlet state.

176 d malachite green possessing a central eight-membered ring in three steps.

177 of a large diversity of highly functional 7-membered rings in good yields up to 95%.

178 4-disubstituted carbo- and heterocyclic five-membered rings in high yields and with good to excellent

179 (S)-cis configuration of the two central six-membered rings in protoberberine BIA compounds.

180 e moieties with differently substituted five-membered rings in the backbone of the newly formed heter

181 -substituted benzene units to construct five-membered rings in this work provides a unique entry to n

182 abolite, comprises a linear array of 10 five-membered rings in two pentacyclic regions that derive fr

183 tramolecular hydroacylation has favored five-membered rings, in preference to four membered rings.

184 m the conformation adopted by a formal eight-membered ring including both N and O atoms (i.e., crown,

185 A five-membered ring indene skeleton is also prepared via olefi

186 le or multiple hydrophilic moieties on a six-membered ring inhibited the Hh pathway in both Hh-depend

187 By low-temperature NMR spectroscopy the six-membered-ring interconversion could be frozen at 103 K a

188 sp(3) C-H bonds of methyl groups via a five-membered ring intermediate over the sp(2) C-H bonds of a

189 addition with the nitrone, generating a five-membered ring intermediate.

190 ssible cycloadditions, a pair of novel three-membered ring intermediates has been discovered.

191 N-N bond formation, producing unstable five-membered ring intermediates that spontaneously dehydrate

192 Incorporation of a five-membered ring into a helicene framework disrupts aromati

193 l syn-pentane interactions which force a six-membered ring into a twist-boat conformation.

194 ologies which convert readily available five-membered rings into strained four-membered rings.

195 ed 4-thiazole substituents that form a seven-membered ring intramolecular hydrogen bond with a 5-posi

196 coupling approach, wherein the central seven-membered ring is synthesized at a late stage.

197 blished that the alpha-position of the three-membered ring is the favored deprotonation site.

198 for one of the complexes showed that the six-membered ring is very distorted and the thiophene ring i

199 highly diastereoselective synthesis of five-membered rings is achieved from the reaction of the corr

200 he resulting bistetracene analogue with five-membered rings is comprehensively investigated by single

201 ation of the bistetracene analogue with five-membered rings is kinetically controlled while an "expec

202 trolled while an "expected" product with six-membered rings is thermodynamically more favored.

203 The five-membered ring lactam intermediates in these synthetic ro

204 hree-component reaction, giving rise to nine-membered-ring lactones.

205 lar cross-coupling to furnish the desired 30-membered ring macrocycle containing the critical (Z,Z,E)

206 g metathesis reactions, generating 14- to 21-membered ring macrocyclic alkenes in 40-70% yield and 96

207 logs revealed that TylHI strictly prefers 16-membered ring macrolides bearing the deoxyamino sugar my

208 Notably, the 18-membered-ring moiety of pacritinib-a potent anti-cancer

209 The cis-isomers align in the main 12-membered ring (MR) channel of GME.

210 eophiles, including (1) unhindered, (2) five-membered-ring N-heterocycle-containing, and (3) alpha-te

211 rom a strand in sequence, featuring up to 20-membered ring native chemical ligation transition states

212 core, Ni(mu-E(PhX))(mu-S'(N2))Fe, to a five-membered ring Ni-O-E-Fe-S', where an O atom inserts betw

213 yrimidine nucleobases, ranging from 5- to 12-membered ring nucleoside analogs, are generated in excel

214 ed and further elaborated into the final six-membered ring nucleosides via nucleobase incorporation a

215 ate, the reaction occurs at the central four-membered ring of biphenylene.

216 budding sites suggest that formation of a 12-membered ring of ESCRT-I molecules is a geometry-depende

217 es has been tailored to bind the small, four-membered ring of oxetanocin-A over larger substrates.

218 ization procedures leading to the core seven-membered ring of the iboga skeleton, a cyclization that

219 this alkynylaldehyde, to construct the eight-membered ring of the target, unexpectedly provided a cyc

220 to compare the aromaticity in both the five-membered rings of 33, 34, 36 and 1,6-dioxa-6a-chalcopent

221 with the fraction of H(+) sites sharing six-membered rings of chabazite (CHA) zeolites.

222 , resulting in weaker aromaticity of the six-membered rings of the buckybowl skeleton.

223 ains carried by the beta-lactam and the five-membered rings of the carbapenem core.

224 ly proposed "aromatic character" of the "two-membered rings" of the acetylene and butatriene molecule

225 ( summation operator) concentrations of 5/6-membered ring OH-PAHs in liver were smaller [mean of 931

226 open-cage fullerene, MMK-9, with an open 12-membered ring on its surface and silver(I) salts have be

227 hlorin-type PMPs containing either two eight-membered rings or an eight-membered ring and an imidazol

228 ctions directed toward the syntheses of five-membered rings, other carbocycles and, finally, heterocy

229 modeling suggest that 7 was formed via a six-membered ring oxathiaphosphenine intermediate rather tha

230 nine intermediate rather than the usual four-membered ring oxathiaphosphetane of 2-6.

231 ophile attack for 2,3-trans-substituted five-membered ring oxocarbenium ions is strongly influenced b

232 Nucleophilic attack on seven-membered-ring oxocarbenium ions is generally highly ster

233 compared to that of reactions involving six-membered-ring oxocarbenium ions.

234 introduced at the N(1) position of the five-membered ring, potentially mimicking any residues.

235 al characterizations of the cyclic 6- and 12-membered ring precursors are also described.

236 nicellin natural products from a number of 9-membered-ring precursors.

237 nce of oxygen, leads to formation of a seven-membered ring product, an overall [4+4-1] reaction.

238 ruthenium-based system that affords the six-membered ring products was also developed.

239 Five- and six-membered ring products were obtained in good to excellen

240 ssed by PikAIII-TE and failed to generate 12-membered ring products.

241 bond-localization within the connecting six-membered ring resulted in reduced antiaromaticity of bot

242 The existence of five-membered rings results in a bowl-shaped geometry, as rev

243 ylation of the C(sp(2))-H bond enabling five-membered ring ruthenacycle intermediates, the cyclic imi

244 enes, which can be converted into other five-membered-ring scaffolds with up to five contiguous stere

245 early 10(6)-fold between the five- and eight-membered ring series.

246 tly thermodynamically disfavored in the five-membered ring series.

247 splays a boat conformation for its Ge-Se six-membered ring ("six-ring"), while the previously known a

248 ross-metathesis reactions, and a strained 14-membered ring stapled peptide by means of macrocyclic ri

249 s primarily high-energy dications with a six-membered-ring structure.

250 All chlorophylls have similar five-membered ring structures, with variations in the side ch

251 ibes the ring opening of more reactive three-membered rings substituted with unsaturations with a par

252 ate, providing a means to convert a simple N-membered ring substrate to either n+1 or n+2 ring adduct

253 copodium alkaloid natural products share a 7-membered-ring substructure and may potentially arise fro

254 ed by reversible photocyclization to a seven-membered ring system (formed as a mixture of diastereome

255 up abilities already established for the six-membered ring system (NHBn >> OH > NBn2), an N,N-dibenzy

256 from the generation of a highly strained ten-membered ring system(8,9).

257 tion and formation of a highly strained four-membered ring system.

258 The reaction produces substituted five-membered ring systems stereoselectively and on preparati

259 ety of heterocyclic systems spanning small 3-membered ring systems to macroheterocycles.

260 3,5-triazinanes, leading to the five- or six-membered ring systems under mild conditions in yields up

261 re converted to trans-disubstituted 5- and 6-membered ring systems with perfect diastereoselectivity

262 strained by incorporation into six- or seven-membered ring systems, by addition of a lithiated primar

263 has been designed to construct bridged seven-membered-ring systems that are otherwise challenging to

264 the enamine-iminium complex by forming a six-membered ring that favors one helicity of the electrocyc

265 on to alkylate at C2, crafting a fused seven-membered ring that is characteristic of the pentacyclic

266 ded one-dimensional lines of five- and eight-membered rings that are domain boundaries and stacking f

267 al carbon scaffolds comprising six- and four-membered rings that pack within a pseudosquare lattice p

268 found with many of the oxygen-containing six-membered rings that were investigated.

269 ving five-, six-, seven-, eight-, and twelve-membered rings, the un-rearranged dibenzothiophene Diels

270 tively with the resonance energy of the five-membered ring; the nonaromatic cyclopentadiene derivativ

271 and three-component domino reaction of four-membered ring thionation reagents such as 2,4-bis(4-meth

272 he diastereoselective formation of the seven-membered ring through a Friedel-Crafts triflation and a

273 ng process for cascade formation of two five-membered rings through spiroannulation followed by cycli

274 macophore tolerates ring expansion of the 13-membered ring to 14-,15-, and 16-membered rings containi

275 ompetition reactions showed that these seven-membered ring trans-alkenes underwent [4+2] cycloadditio

276 Seven-membered-ring trans-alkenes undergo rapid, uncatalyzed c

277 the ribosome would proceed through an eight-membered ring transition state, involving a proton shutt

278 In the case of benzylamine, the eight-membered ring transition structure that leads to the pro

279 of the pinacol group was observed in the six-membered ring transition structure toward the allenylami

280 es have been elaborated from a panel of five-membered ring trifluoromethylated amino acids (Tfm-AAs)

281 tead of the thermodynamically favorable five-membered rings under appropriate conditions.

282 r comprises a fluorene lower half and a five-membered-ring upper half; the upper-half ring is fused t

283 l lineNH and cis-1,3-butadiene to form a six-membered ring was examined by quantum calculations.

284 The influence of four-membered ring was examined using spectroscopy, crystallo

285 red to one where it was tethered by an eight-membered ring was less than 100-fold, suggesting that fu

286 almost planar N-arylamine and a planar four-membered ring, was revealed by both AM1 calculations and

287 Lactones containing five-, six-, and seven-membered rings were successfully synthesized, and no ove

288 es ranging in size from twelve- to seventeen-membered rings were synthesized in moderate to high yiel

289 d nitrogen heterocycle is replaced by a 9-12-membered ring, were made by an unactivated Smiles rearra

290 ization of 6pi-electrons over the BC2N2 five-membered ring, which thus indicates the aromatic propert

291 e internal SiC(2) and two outer M-Si-C three-membered rings, which are fused via two Si-C bonds.

292 Three- and four-membered rings, widespread motifs in nature and medicina

293 distinct local structures, situated in the 8 membered ring windows of the side pockets.

294 cally characterized PMPs containing an eight-membered ring with their solution-state optical properti

295 t in five-, six-, seven-, eight-, and twelve-membered rings with substituted N-phenylmaleimides are c

296 been applied for the synthesis of 12- to 23-membered rings with varying amino acid compositions in o

297 yclization reaction, forming a bridged seven-membered ring within a polycyclic system.

298 of natural origin is a 1,2-trans fusion of 5-membered rings within a [3.3.0]-bicycle, a motif present

299 ine derivative salts with fused five and six-membered rings (X-ray) were obtained via modification of

300 It is the second C(7)H(7) isomer with a five-membered ring yet to be detected, the other being vinylc