ライフサイエンスコーパス: acetal

1 on to give tert-alpha-arylated aldehydes (as acetals).

2 g a gamma-butyrolactone-derived silyl ketene acetal.

3 ring closure) leading to the dihydrodipyrrin-acetal.

4 carbenoid complex, generated from propargyl acetal.

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

6 ondensation of the resulting dihydrodipyrrin-acetal.

7 erwent a second allylation with aldehydes or acetals.

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

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

10 stereodivergent resolution to diastereomeric acetals.

11 pper-catalyzed alkynylations of benzopyranyl acetals.

12 luoromethylphenyl)sulfonyl-substituted alkyl acetals.

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

14 with ethoxymethyl chloride and formaldehyde acetals.

15 philes and converted them into corresponding acetals.

16 s-oxycyclization to afford tricyclic bridged acetals.

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

18 nd AgBF(4), respectively, via in situ-formed acetals.

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

20 tivation pathway of five-membered semicyclic acetals.

21 ate between aldehydes and thiopyridyl ketene acetals.

22 ves from indoles and nitrogen-functionalized acetals.

23 yields six-membered ring diisopropylsilylene acetals.

24 on of terminal alkynes to racemic isochroman acetals.

25 y cyclize divinyl ethers to analogous cyclic acetals.

26 itions to form highly functionalized nitroso acetals.

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

28 fford valuable N-methyl amino acids and N, O-acetals.

29 e transition state during the degradation of acetals.

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

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

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

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

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

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

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

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

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

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

40 f esters, nitriles, alkyl halides, epoxides, acetals, alkenes, aryl halides, and silyl ethers.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

55 scent PARAFAC components and volatile acids, acetals and carbonyls contents revealed the predominance

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

74 ion leads to the formal construction of N, O-acetals, and the remaining azide functionality is a usef

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

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

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

78 The formed N-O-acetals are competent acylimine precursors.

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

80 .2.2]octadiene-type products and benzoxepine acetals are formed in this reaction, in ratios and yield

81 N,OTMS-acetals are obtained diastereoselectively from additions

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

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

84 iols involves formation of dialkylstannylene acetals as intermediates.

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

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

87 and diastereoselective formation of sulfenyl acetals bearing multiple stereogenic centers is reported

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

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

90 s obtained as dimethoxymethane, its dimethyl acetal, by selective reduction of carbon dioxide at mode

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

92 Acetals can be considered activating groups of the carbo

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

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

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

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

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

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

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

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

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

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

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

104 dable metathesis polymers is presented using acetal-containing enyne monomers.

105 rearrangement and a late-stage Stille ketene acetal coupling.

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

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

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

109 enzannulation transformations of epoxide and acetal derivatives.

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

111 nobenzoquinone dienophile and a silyl ketene acetal diene.

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

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

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

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

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

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

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

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

120 The preparation of these aldehydes/acetals, especially containing a tert-benzylic stereocen

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

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

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

124 Ugi reaction with aminoacetaldehyde dimethyl acetal, followed by acid-mediated cyclization to generat

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

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

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

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

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

130 borylation reactions involving oxidation and acetal formation.

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

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

133 porpholactol dimer that is linked through an acetal functionality.

134 ne acetal employed but independent of ketene acetal geometry.

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

136 1,2-diol moiety masked as an isopropylidene acetal group and long alkyl chains comprised of 12 and 1

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

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

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

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

141 Upon exposure to an acidic environment, the acetal groups are cleaved and the gold nanoparticles bec

142 ated with thiolated dextran, and hydrophobic acetal groups are installed through direct covalent modi

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

144 CO(2) at room temperature via the bis(silyl)acetal, H(2)C(OSiPh(3))(2).

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 cyclic, chiral alpha-trifluoromethylated N,O-acetals having a protected cis-diol moiety has been read

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

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

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

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

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

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

158 rearrangement) with H(2) O(2) , followed by acetal hydrolysis, to produce a green fluorescent molecu

159 ike catalyst for substrate selective diethyl acetal hydrolysis.

160 zed from myo-inositol and dimethyl d-camphor acetal in 14 steps.

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

162 ihydropyran and 1,3-disubstituted isochroman acetals in good to excellent yield and with high levels

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

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

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

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

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

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

173 nd vanillin for MPX and acetaldehyde diethyl acetal, isobutyl acetate, ethyl isovalerate and guaiacol

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 Protection of the aldehyde as a 1,3-dioxane acetal led to strong fluorescence emitted by the coumari

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

183 grafts through an acid-sensitive benzylidene acetal linkage.

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

185 ties to the polysaccharide through cleavable acetal linkages.

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

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

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

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

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

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

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 We describe the 3-iodopropyl acetal moiety as a simple cleavable unit that undergoes

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

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

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

198 ple method for synthesizing acyclic diketene acetal monomers from diols and vinyl ether, and their po

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

200 in the formation of the polycyclic organotin acetals obtained.

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

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

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

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

205 -catalyzed cyclization of cyclic and acyclic acetals of alkynylaldehydes that leads to indenone forma

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

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

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

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

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

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

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

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

214 igh selectivity between subtly nonequivalent acetal oxygen atoms.

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

216 First, an oxetane acetal persists in concentrated mineral acid (1.5 M DCl

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

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

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

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

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

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

223 ion significantly stabilized the 1,3-dioxane acetal protecting group, allowing for specific stimulus-

224 presence of benzyl ether and isopropylidene acetal protection have also been reported here.

225 The acetal protective groups were cleaved with refluxing for

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

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

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

229 The requisite substrates for the vinyl acetal rearrangement were synthesized via ring-closing o

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

231 2- versus 3-position in the dihydrodipyrrin-acetals, respectively, (2) the method of synthesis of th

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

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

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

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

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

237 of carbon nucleophiles such as silyl ketene acetals, silyl ketene imines, a silyl cyanide, an alkyny

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

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

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

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

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

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

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

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

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

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

248 ing protection as the corresponding dimethyl acetals, the iodofulvenes were metalated with Bu(3)MgLi

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

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

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

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

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

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

255 riggered the aldehyde-protecting 1,3-dioxane acetal to slowly decompose, leading to the inhibition of

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

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 Rearrangement of vinyl acetals under a variety of conditions resulted in cis- a

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 The absence of a tether in the acetal unit considerably outpaces any 1,5-H shift and in

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

269 onality tolerance (alkenes, esters, ketones, acetals, unprotected hydroxyl groups, and phosphines) ha

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

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

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

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

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

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

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

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

278 ucleophilic substitutions of tetrahydropyran acetals were investigated.

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

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

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

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

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

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

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

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

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

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

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

297 reaction of O-acetyl analogues of these N,O-acetals with triflic acid in 1,1,1,3,3,3-hexafluoro-2-pr

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