ライフサイエンスコーパス: acetal

1 ring closure) leading to the dihydrodipyrrin-acetal.

2 carbenoid complex, generated from propargyl acetal.

3 e bonds such as geminal diol, disulfide, and acetal.

4 ubstituted (propanoate-derived) silyl ketene acetal.

5 ondensation of the resulting dihydrodipyrrin-acetal.

6 omatics, silyl enol ethers, and silyl ketene acetals.

7 with ethoxymethyl chloride and formaldehyde acetals.

8 s-oxycyclization to afford tricyclic bridged acetals.

9 stabilization of the resulting N,N- and O,N-acetals.

10 ions of phenol-derived Rychnovsky-type mixed acetals.

11 tivation pathway of five-membered semicyclic acetals.

12 ate between aldehydes and thiopyridyl ketene acetals.

13 ves from indoles and nitrogen-functionalized acetals.

14 on of terminal alkynes to racemic isochroman acetals.

15 y cyclize divinyl ethers to analogous cyclic acetals.

16 itions to form highly functionalized nitroso acetals.

17 and amines, alkenes, unsaturated esters, and acetals.

18 e transition state during the degradation of acetals.

19 size of the substituents on the silyl ketene acetals.

20 recedented migration-fragmentation of ketals/acetals.

21 Z- and E-enamides, an amide, and N,O-ketene acetals.

22 is of tosylates but not in the hydrolysis of acetals.

23 been applied to the synthesis of chiral N,N-acetals.

24 stereodivergent resolution to diastereomeric acetals.

25 pper-catalyzed alkynylations of benzopyranyl acetals.

26 luoromethylphenyl)sulfonyl-substituted alkyl acetals.

27 the formation of fenestrane 2 from aromatic acetal 1 is reported.

28 n-reaction product (e.g., the anomeric mixed acetal 10).

29 -stabilized oxocarbenium ions generated from acetals 14a-e or 15a-e is controlled by the stereoelectr

30 cyclizations of unsaturated alpha-dithianyl acetals 14a-e or 15a-e.

31 Benzoyl-S,O-acetals 1a and 1b were used as chiral auxiliaries to ach

32 ions, as shown in the photo reactions of the acetal 9.

33 ifunctional ligand with an attached pyruvate acetal, a ligand for human amyloid P component, and conj

34 owed by reductive opening of the benzylidene acetal afforded the disaccharide diol acceptor.

35 ldehydes, esters, heterocycles, silyl ketene acetals, alcohols) is then discussed in the context of m

36 ve deprotection of the resulting benzylidene acetal allowed for swift access to the delta-lactone.

37 e (DDQ) with silyl enol ethers, silyl ketene acetals, allylsilanes, enamino esters, and diazomethanes

38 ng for the first time a sterically demanding acetal, an intramolecular chemoselective acylation to ac

39 rst-order kinetic dependence on silyl ketene acetal and 1-naphthaldehyde and a zeroth-order dependenc

40 Here we present a series of 4',6'-O-acetal and 4'-O-ether modifications on glucopyranosyl ri

41 to-dioxinone with dimethylformamide dimethyl acetal and a range of magnesium acetylides gave the corr

42 nges on a Hosomi-Sakurai coupling of complex acetal and allylsilane coupling partners, followed by DD

43 of an aldol-like coupling between a dimethyl acetal and an N-acetylthiazolidinethione for the direct,

44 yields for formation of the dihydrodipyrrin-acetal and bacteriochlorin underpins evaluation of synth

45 The alkenyl acetal and ketal substrates show dramatically faster rat

46 and siloxane with no detection of bis(silyl)acetal and methyl silyl ether intermediates.

47 Protection of the hydroxy group as a THP acetal and oxidative cleavage of the C,C-double bond pro

48 other CH(2)O molecules and the formation of acetal and polyacetal intermediates, which inhibits the

49 of an aldehyde with a trimethylsilyl ketene acetal and the oxazaborolidinone prepared from N-Ts-(S)-

50 Utilizing acetal and vinyl substituted diazides, the corresponding

51 esters, while CHT raised the levels of total acetals and alcohols.

52 Different alkyl and aryl substituted acetals and aldehydes have been tested in the reaction w

53 step from easily accessible phenylpropargyl acetals and benzaldimine substrates in the presence of a

54 er acidic conditions typical for hydrolyzing acetals and constitute orthogonal protecting groups with

55 methyldinocap), in 2009, BTH increased total acetals and esters, while CHT raised the levels of total

56 tection of carbonyls and the deprotection of acetals and ketals involve the participation of a water

57 ticipation of a water molecule: formation of acetals and ketals is a dehydration process, whereas the

58 presented by the TFA-mediated conversion of acetals and ketals to carbonyls has never been previousl

59 trated that water is not required to convert acetals and ketals to the corresponding carbonyls.

60 ky silanes results in formation of bis(silyl)acetals and methyl silyl ethers as well as siloxanes and

61 disubstituted silyl synthons to afford silyl acetals and Rh-catalyzed ortho-C-H silylation to provide

62 e of kinetically reversible adducts, such as acetals and sulfonates, so that sample preparation steps

63 lective [4 + 2] cycloaddition of isochromene acetals and vinylboronates.

64 when calculated energies of hemiaminals (N,O-acetals) and aminals (N,N-acetals) were compared with ex

65 hioethers, alkyl chlorides, acrolein diethyl acetal, and isochroman.

66 propargyl alcohol, bromoacetaldehyde diethyl acetal, and OEGs or PEGs was developed as a convenient p

67 would be possible with an oxopyridyl ketene acetal, and this was confirmed experimentally, leading t

68 functionalities such as alkynes, aldehydes, acetals, and azides.

69 h C-nucleophiles (enamines, silylated ketene acetals, and enol ethers) have been determined photometr

70 boxylic acids esters, benzenoids, furans and acetals, and reduced fermentation aroma compounds.

71 eteroaryl, and cyclopropyl ethers, mixed O,O-acetals, and S,S,O-orthoesters.

72 eta,gamma-unsaturated CH(2)=CHCH(2)CH(OR)(2) acetals, and they cyclize divinyl ethers to analogous cy

73 The effect of structural variations in acetal- and ketal-based linkers upon their degradation k

74 ction of 1 followed by an intramolecular N,O-acetal- and N,N-aminal formation, respectively, which pr

75 These N-tert-butanesulfinyl 2-amino acetals are convenient precursors for the TMSOTf-promote

76 .2.2]octadiene-type products and benzoxepine acetals are formed in this reaction, in ratios and yield

77 N,OTMS-acetals are obtained diastereoselectively from additions

78 The latter acetals are photochemically inert but can be converted i

79 of ketones via enaminones using DMF dimethyl acetal as carbon source.

80 iols involves formation of dialkylstannylene acetals as intermediates.

81 yde and tetrazolo[1,5-a]quinoline-3-dimethyl acetal at room temperature in methanol as solvent.

82 These Bis-Acetal-Based Substrates (BABS) bear a hemiacetal aglycon

83 syl nucleoside analogues from acyclic N,OTMS-acetals bearing pyrimidine and purine bases.

84 ] for self-condensation of a dihydrodipyrrin-acetal (bearing a geminal dimethyl group in the pyrrolin

85 ntially by inserting into an inward-pointing acetal C-H bond of H.

86 roup at the C2-position on a minimal oxepane acetal can reproduce the PES for the septanoside 1.

87 Acetals can be considered activating groups of the carbo

88 acceleration of ionization in more flexible acetals can be up to 200-fold when compensated for induc

89 eeves, which are too flexible in the case of acetals can be used in OSTK rods.

90 iates that accumulate positive charge at the acetal carbon atom.

91 the formation of a less reactive full cyclic acetal catalyzed by the acidity of the DNPH solution and

92 spiroketal subunit, the configuration at the acetal center in both structures is unchanged and is con

93 tals with high S(N)2-like selectivity at the acetal center in the presence of Me2BBr and thiophenol.

94 mplete retention of configuration at the C1' acetal center.

95 r content of furans, aldehydes, ketones, and acetals, compared with unpressurised wines after 9 month

96 (N-S) self-condensation of a dihydrodipyrrin-acetal complements a prior Eastern-Western (E-W) route.

97 iles add efficiently to a Fmoc-protected N,O-acetal compound.

98 The structurally simplified C(11-15)-acetal congener (+)-20Z also proved potent albeit reduce

99 A series of fused-bicyclic acetals containing a disiloxane ring was investigated to

100 Experiments with alpha-boryl acetals containing a latent fluorophore clearly demonstr

101 , a thermally promoted methylenecyclopropane acetal cycloaddition, and a Pd-catalyzed cycloaddition o

102 azolidine-2-thiones to dimethyl and dibenzyl acetals depends on the hydroxyl protecting group.

103 16 followed by base mediated alkylation and acetal deprotection gave galbonolide B 1.

104 The successful acetal deprotection of the synthesized trans-3 bisadduct

105 enzannulation transformations of epoxide and acetal derivatives.

106 Acetals derived from aryl, unsaturated, and aliphatic al

107 , whereas the tert-butyldimethylsilyl ketene acetals derived from bulky esters of alpha-methoxyacetic

108 Mukaiyama-aldol type reactions of acetals derived from enolizable aldehydes with FeCl3.6H2

109 rs included triethylsilyldiperoxyketals and -acetals derived from geminal dihydroperoxides and from a

110 In general, the trimethylsilyl ketene acetals derived from methyl glycolates with a large prot

111 hod employing triethylsilylperoxyketals and -acetals derived from ozonolysis of alkenes.

112 nobenzoquinone dienophile and a silyl ketene acetal diene.

113 ble materials, features a diastereoselective acetal-directed cyclopropanation of an electron-deficien

114 This traceless acetal directing group strategy for catalytic ortho-C-H

115 nucleophilic addition to silicon removes the acetal directing groups and directly provides unmasked p

116 equivalents, which allow not only removal of acetal directing groups but also introduce useful functi

117 ion metal catalysts and the use of traceless acetal directing groups, has been employed to provide fa

118 species and an alpha,beta-unsaturated ketone-acetal (e.g., 1,1-dimethoxy-4-methylpent-3-en-2-one).

119 pyrrolic substituents in the dihydrodipyrrin-acetal (electron-withdrawing, electron-donating, or no s

120 are highly dependent upon the type of ketene acetal employed but independent of ketene acetal geometr

121 building blocks of organic synthesis such as acetals, enolates, Michael acceptors, acylating reagents

122 H2 along with formation of bis(triethylsilyl)acetal ((Et3SiO)2CH2, 7).

123 groups of aromatic compounds in high yields acetals, ethanol and ethyl aromatics, and methyl aromati

124 coupling conditions such as esters, ketones, acetals, ethers, silyl ethers, and dimethylamino groups.

125 e enamides to deallylated amides through N,O-acetal exchange.

126 with 2-naphthols in preference to the mixed acetal formation and subsequent [3,3] sigmatropic rearra

127 eoselective oxy-Michael addition/benzylidene acetal formation coupled with a selective axial oxocarbe

128 onstrate that O-substitution by (glycosylic) acetal formation greatly increased the chemical stabilit

129 ethylsilyl ester formation, bis-silyl ketene acetal formation, and TMSOTf-catalyzed Mukaiyama aldol a

130 borylation reactions involving oxidation and acetal formation.

131 of C1' followed by retro-aldol cleavage and acetal formation.

132 sometimes quantify the sulfite, hydrate, and acetal forms of the carbonyl compounds.

133 d in the context of preparing polycyclic N,O-acetals from simple 1-(aminomethyl)-beta-naphthols and 2

134 f the remaining 2'-[4-(N-methylamino)benzyl] acetals from the RNA oligonucleotide was effected in buf

135 aryl, alkoxy, chloromethyl, phthalimido, and acetal functional groups.

136 porpholactol dimer that is linked through an acetal functionality.

137 ne acetal employed but independent of ketene acetal geometry.

138 plasmenyl cyclophosphatidic acid and a mixed acetal glycolipid, with the latter subsequently being is

139 1,2-diol moiety masked as an isopropylidene acetal group and long alkyl chains comprised of 12 and 1

140 e where the alkoxy group was tethered to the acetal group by a five-membered ring compared to one whe

141 nogated ensemble has been developed by using acetal group linked gold nanoparticle capped mesoporous

142 wo parts: radical, anionic, and silyl ketene acetal group transfer polymerization (SKA-GTP) of vinylp

143 The acid-lability of the acetal groups allows the release of therapeutics under a

144 The physical and chemical behavior of these acetal groups can be adjusted by modifying their stereoe

145 The acetal (H1C1) groups suffice to spectroscopically resolv

146 oring CH4, and Ph3SiH favoring the bis(silyl)acetal, H2C(OSiPh3)2.

147 y R3SiH to afford sequentially the bis(silyl)acetal, H2C(OSiR3)2, and CH4 (R3SiH = PhSiH3, Et3SiH, an

148 ng reaction of quinoline-derived allylic N,O-acetals has been studied using a combination of structur

149 ic acid-catalyzed cyclization of unsaturated acetals has been utilized for the synthesis of functiona

150 The resulting oligocyclic N,O-acetals have been used as excellent chiral building bloc

151 Nucleophilic substitution reactions of acetals having benzyloxy groups four carbon atoms away c

152 as for the HCl-promoted synthesis of 2-amino acetal hydrochlorides and alpha-amino ketone and alpha-a

153 The difference in rates of acetal hydrolysis between a substrate where the alkoxy g

154 The acceleration of acetal hydrolysis by an alkoxy group is better explained

155 indicate that an alkoxy group can accelerate acetal hydrolysis by up to 20-fold compared to substrate

156 tabilization, an alkoxy group can accelerate acetal hydrolysis by up to 200-fold.

157 Comparison of the rates of acetal hydrolysis in the assembly with the rate of the r

158 ike catalyst for substrate selective diethyl acetal hydrolysis.

159 tion-controlled reducing reagent for acyclic acetal (i.e., MOM, MEM, SEM, and BOM) protected alpha-hy

160 r formed from the in situ generated dimethyl acetal in the presence of triflic acid undergoes alkylat

161 ramolecular host catalyzes the hydrolysis of acetals in basic aqueous solution.

162 s afforded new N-tert-butanesulfinyl 2-amino acetals in good to excellent yield.

163 eactions of propargyl acetates and propargyl acetals in the chiral ligand-controlled Rautenstrauch re

164 and thioesters add in high yield to dimethyl acetals in the presence of silyl trifluoromethanesulfona

165 ation of indoles with N-protected aminoethyl acetals in the presence of TES/TFA is reported.

166 rates, experiments with 4-alkoxy-substituted acetals indicate that an alkoxy group can accelerate ace

167 ves initial hydroxylation of substrate to an acetal intermediate and its subsequent attack onto an Fe

168 approach, without isolation of the bicyclic acetal intermediates.

169 r the conversion of a late-stage benzylidene acetal into a primary alcohol and a secondary benzoate e

170 od is suitable for a direct isomerization of acetals into the thermodynamically preferred isomer as l

171 The benzylidene acetal is found to stabilize the alpha-anomer of galacto

172 rho value for the hydrolysis of benzylidene acetals is about -4.06, which is comparable to an SN1-li

173 l and important skeleton of the bicyclic N,O-acetals is described.

174 of tetracyclic systems containing a bis-N,O-acetal junction.

175 other hydrolyzable bonds, such as anhydride, acetal, ketal, or imine, in their backbone structures.

176 between allyl or allenyl boronic esters and acetals, ketals, or aminals have proceeded in high yield

177 ported for catalytic alkynylation of acyclic acetals/ketals, and is uniquely enabled by the applicati

178 tain acid-labile linkages such as esters and acetals/ketals.

179 ully generated from fluorinated O-acetyl-N,O-acetal l-tartaric acid derivatives.

180 ymmetrical monomethylated cyclic unsaturated acetal leads to hyperolactone C, where ylide formation-r

181 gs linked to the desosamine glycoside via an acetal linkage (referred to as "carbolides") in a regios

182 grafts through an acid-sensitive benzylidene acetal linkage.

183 doline, a bridged [3.3.1]azabicycle, two N,O-acetal linkages, and six stereogenic centers.

184 ties to the polysaccharide through cleavable acetal linkages.

185 ment of water-soluble siRNA carriers, namely acetal-linked amino-dextrans, with various amine structu

186 The hydrolysis of acetal linker at acidic environment makes the gold nanop

187 ached through either slow- or fast-degrading acetal linker.

188 agnitude depending on the degree and type of acetal modification.

189 rinotecan, in the compartment containing the acetal-modified dextran polymer and the pH dependent rel

190 partment containing a pH responsive polymer, acetal-modified dextran, and PLGA (polylactide-co-glycol

191 ccharide, was modified at its hydroxyls with acetal moieties such that it became insoluble in water b

192 ntaining the peroxide, monoperoxyacetal, and acetal moieties was developed based on the acid-catalyze

193 e of baumycins is the presence of an unusual acetal moiety appended to daunosamine, which is hydrolyz

194 agmentation with elimination of the appended acetal moiety as a whole.

195 her backbone in lieu of the (isopropylidene) acetal moiety characteristic for traditional TADDOL's.

196 embedded within the bicyclo[5.2.1]decane-N,O-acetal moiety of sieboldine A was a formidable challenge

197 Histidine-derived hydrazide acetal monomers (3-dimethoxymethylbenzoyl)-L-histidine m

198 ional groups such as esters, amides, ethers, acetals, nitriles, and tertiary amines and, therefore, s

199 to the steric bias engendered by the mesityl acetal of 87 and contact ion pairing of the intermediate

200 aldol addition of the tert-butylsilyl ketene acetal of tert-butyl propanoate with 1-naphthaldehyde is

201 ctionalized alkylimines with the silylketene acetal of the above lactone, whereas 2,3-cis-morpholines

202 sis includes three-component condensation of acetals of 2-azidoaldehydes with urea or methylurea and

203 ing revealed, however, that products are the acetals of the unsaturated reagent rather than the desir

204 The effect of a 4,6-O-alkylidene acetal on the rate of acid-catalyzed hydrolysis of methy

205 rmation of the delta-carbonyl group into the acetal one.

206 nantioselective substitution of silyl ketene acetals onto 1-chloroisochromans.

207 Indanes can be isolated as an acetal or alcohol in up to 78% ee.

208 cs of polymeric nanogels that contains these acetal or ketal moieties as cross-linking functionalitie

209 ctive reduction of CO2 into either bis(boryl)acetal or methoxyborane depending on the hydroborane use

210 ive difluoro or monofluoroacetyl-substituted acetals or corresponding difluoromethylphosphonate- and

211 aneous hydrolysis conditions, the alkylidene acetal, or its 7-carba analog, retards hydrolysis with r

212 igh selectivity between subtly nonequivalent acetal oxygen atoms.

213 alkylation, installation of the methylidene acetal, palladium-catalyzed O-arylation, and C3,C3'-deca

214 of POEs using air- and moisture-stable vinyl acetal precursors is presented.

215 ation between ZnCl(2) and thiopyridyl ketene acetals prior to aldehyde addition for optimal reaction

216 ies, and beta-OR elimination to generate the acetal product.

217 addition, the highly functionalized nitroso acetal products can be hydrogenolyzed selectively to for

218 Novel bis- and tetraepoxides and bicyclic acetal products, arising from rearrangements of anthrace

219 The use of MOM-protected alcohols and acetal-protected aldehydes enables ether formation witho

220 ehavior of mannosyl iodides lacking bridging acetal protecting groups.

221 The acetal protective groups were cleaved with refluxing for

222 reaction of aldehydes and thiopyridyl ketene acetals provides a versatile, highly diastereoselective

223 ehydes, including those generated from their acetals, provides reversible 2'-O-protected ribonucleosi

224 n ketone-derived hydrazones and silyl ketene acetals, providing the beta,beta-disubstituted beta-amin

225 alpha-Boryl ethers, carbonates, and acetals, readily prepared from the corresponding alcohol

226 Hemiacetal 9 can be converted to an acetal, reduced to an ether, or converted to bis-alkylox

227 2- versus 3-position in the dihydrodipyrrin-acetals, respectively, (2) the method of synthesis of th

228 ns of C-4 sulfur-substituted tetrahydropyran acetals revealed that neighboring-group participation do

229 d by regioselective reductive opening of the acetal ring in the parent 4(I),6(I)-O-benzylidene deriva

230 Regioselective cleavage of the acetal ring of 1,3-benzylidene 2-C-methylerythritol sily

231 nt, (c) fragmentation of the O-C bond in the acetal ring, or (d) fragmentation with elimination of th

232 rgman cyclization in enediynes equipped with acetal rings mimicking the carbohydrate moiety of natura

233 C1' to C4' cyclization where the OTMS of the acetal serves as the nucleophile to generate 2'-oxynucle

234 amine moieties and structural composition of acetals showed high in vitro transfection efficiency and

235 ntial amounts of a hemicarcerand lacking one acetal spanner suggests that (3)PN decays preferentially

236 s [3,3]-sigmatropic rearrangement of a mixed acetal species which is formed in situ under the reactio

237 of [2.2]para-cyclophanes with cyclic ketene acetals, specifically 5,6-benzo-2-methylene-1,3-dioxepan

238 oduct pH, to induce hemiacetal formation and acetal stabilization or induce and stabilize carbonyl sp

239 ositol orthoformate to the corresponding 1,3-acetal, stereospecific introduction of the amino group v

240 toesters possessing gamma-cyclic unsaturated acetal substitution, followed by acid-catalyzed eliminat

241 n reactions or, alternatively, by semicyclic acetals substitutions.

242 eneration of oxocarbenium intermediates from acetal substrates at low temperatures.

243 The structure of the baumycin acetal suggests that it is likely derived from an unknow

244 the alkoxy protecting group (OMe, OPMB, PMP acetal, tetrahydropyran, and OTBS) present in the boron

245 covery and the subsequent rational design of acetals that serve as chiral auxiliaries on the allene i

246 e, which then catalytically transformed into acetal, the secondary product.

247 lective allylation reactions of silyl ketene acetals, the silicon enolates of esters, to form product

248 alpha-Oxy radicals generated from benzylic acetals, TMSCl, and a mild reductant can participate in

249 onamide employing dimethylformamide dimethyl acetal to afford an enaminone that can react intramolecu

250 aled that the TFA-mediated transformation of acetal to aldehyde occurs via a hemiacetal TFA ester int

251 tage of the ability of the 4,6-O-benzylidene acetal to control the stereochemistry of the beta-D-glyc

252 ated oxidative cyclization of a silyl ketene acetal to generate an all-carbon quaternary center and b

253 reaction between tropones and ketene diethyl acetal to give bicyclo[3.2.2] ring structures, which ope

254 noside unit and of a 2,3-O-diphenylmethylene acetal to install the alpha-L-rhamnopyranosidic linkages

255 inetics are dependent on the ratio of ketene acetals to [2.2]para-cyclophanes as well as the hydropho

256 e addition of glycolate-derived silyl ketene acetals to aldehydes.

257 y available, racemic isochroman and chromene acetals to deliver alpha-chiral oxygen heterocycles.

258 l functionalities, and (3) using other amide acetals to expand the substitution patterns of pyridines

259 nyldiazo carbonyl species react with organic acetals to give E-configured alkyl 3,5-dimethoxy-5-pent-

260 e catalysts for the addition of silyl ketene acetals to N-acylisoquinolinium ions.

261 ty functional theory calculations on nitroso acetal-to-aminal rearrangements reported by Denmark and

262 aponins with dioxolane-type (2 saponins) and acetal-type (16 saponins) substituents were detected in

263 quateraryls were prepared from a ketene-S,S-acetal under mild conditions.

264 lyl ether to alpha,beta-unsaturated aldehyde acetals under Lewis acidic conditions proceeds with good

265 These unusual acetals undergo a C1' to C4' cyclization where the OTMS

266 pha-position of pyrrole ring A and the alpha-acetal unit attached to pyrroline ring B forms the bacte

267 he gem-dimethyl group (with respect to the 1-acetal unit) at the 2- versus 3-position in the dihydrod

268 This reaction takes place via in situ formed acetal using triflic acid and trimethyl orthoformate.

269 serve as substitutes of acrolein or acrolein acetals, utilisation of which has already led to interes

270 chlorin substituents via the dihydrodipyrrin-acetal versus late installation via derivatization of be

271 azides), and N,N-dialkyloxyformamide dialkyl acetal via electrophilic addition of immonium ion to cop

272 stent with the relative degradation rates of acetals vs ketals (correlated to stabilities of 1 degree

273 p procedure, the in situ generated bis(boryl)acetal was shown to be a reactive and versatile source o

274 When cyclopropanone acetal was treated with alkyl azides, N-substituted 2-az

275 The hydrolysis of 4-alkoxy-substituted acetals was accelerated by about 20-fold compared to tha

276 -accelerated alkylation of dialkylstannylene acetals was studied at several levels of theory in the g

277 ucleophilic substitutions of tetrahydropyran acetals were investigated.

278 Eleven new dihydrodipyrrin-acetals were prepared following standard routes.

279 A variety of substituted isochromene acetals were tolerated, furnishing the desired dihydrona

280 f hemiaminals (N,O-acetals) and aminals (N,N-acetals) were compared with experimental equilibrium con

281 les 8(a-j) (silylated enol ethers and ketene acetals) were studied kinetically using photometric moni

282 Aryl-substituted cyclopropanone acetals, when subjected to these conditions, afforded [1

283 generating silyl enol ether or silyl ketene acetal, which are key intermediates in the reaction.

284 tails self-condensation of a dihydrodipyrrin-acetal, which in turn is prepared from a 2-(2-nitroethyl

285 ng the formation of a mixed chiral phosphate acetal, which undergoes a concerted, asynchronous S(N)2'

286 This reaction affords bicyclic acetals, which have been used as key intermediates in th

287 dergo elimination, allowing the isolation of acetals, which subsequently can be hydrolyzed to their c

288 whereas substitution of the 4,6-benzylidene acetal with a 4,6-di-tert-butyl silylidene led to a slig

289 Preparation of a dihydrodipyrrin-acetal with single-isotopic substitution gives rise to a

290 ctions of n-hexyl-substituted cyclopropanone acetals with alkyl azides, a mixture of 2-azetidinones a

291 Reactions of dialkylstannylene acetals with alkyl halides are slow, but rates are enhan

292 ls-Alder reaction of conjugated ketene silyl acetals with benzoquinone.

293 e the Ni-catalysed Csp(3) Suzuki coupling of acetals with boronic acids to generate benzylic ethers,

294 leophilic addition to form chiral cyclic N,S-acetals with moderate to high enantioselectivites.

295 asymmetric Mannich reaction of silyl ketene acetals with N-Boc-amino sulfones has been developed.

296 somerization reaction of alpha-oxoketene-N,S-acetals with propargyl alcohols.

297 stereoselectivities in the substitutions of acetals with strong nucleophiles depended on reaction co

298 promoted coupling of stable, easily prepared acetals with widely available potassium aryl-, alkenyl-,

299 om previously unreported C-alkynyl N-Boc-N,O-acetals, with alpha-substituted beta-keto esters and les

300 limited ionization ability, principally N,O-acetals, without the use of an exogenous reagent have be