- Geminal acylation of α-heterosubstituted cyclohexanones and their ketals
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Geminal acylation of derivatives of cyclohexanone with Br, Cl, F, and OCH3 in the α position, and of their corresponding dimethyl ketals, could not be accomplished to a significant extent following published procedures. The transformation was a
- Pottie, Ian R.,Crane, Sheldon N.,Gosse, Anna Lee,Miller, David O.,Burnell, D. Burnell
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body text
p. 1118 - 1124
(2011/01/09)
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- Photo-cleavage of carbon-carbon bond of α-iodocycloalkanones giving ω,ω-dialkoxyalkanoic ester in alcohol
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The irradiation at λ > 300 nm of α-iodocycloalkanones with a high- pressure mercury lamp in alcohols containing a small amount of water afforded the corresponding ω,ω-dialkoxyalkanoic ester (65-88%) by photochemical cleavage of the C(I)-C=O bond at room temperature. In the case of a commercial fluorescent lamp as the irradiating light source, photochemical ring-opening products were also obtained. The irradiation of 2α-iodo-5α- and 4β-iodo-5β-cholestan-3-ones in methanol gave methyl 2,2-dimethoxy-2,3- seco-5α-cholestan-3-oate and methyl 4,4-dimethoxy-3,4-seco-5β-cholestan-3- oate in 78 and 62% yields, respectively. The photochemical behavior of the cleavage reaction of α-iodocycloalkanones is also discussed on the basis of 2-hydroxycycloalkanone as an intermediate.
- Ji, Shun-Jun,Horiuchi, C. Akira
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p. 1645 - 1652
(2007/10/03)
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- A New α-Iodination of Ketones Using Iodine-Ammonium Cerium(IV) Nitrate in Alcohol or Acetic Acid
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The direct α-iodination of various ketones using iodine-ammonium cerium(IV) nitrate in acetic acid or alcohol gave the corresponding α-iodo ketones in high yields. The effect of cerium salt on the iodination of ketones, and the iodination of 5α-cholestan-3-one using several methods are also discussed. In the reaction of 3,3,5-trimethylcyclohexanone and unsymmetrical ketones, such as 2-hexanone and 2-heptanone, using methanol, ethanol, 1-propanol, and 2-propanol, the regioselective iodination product was obtained. In the case of bromination, the reaction of ketones with bromine and ammonium cerium(IV) nitrate also yielded the corresponding α-bromo ketones.
- Horiuchi, C. Akira,Kiji, Shinji
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p. 421 - 426
(2007/10/03)
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- THE MUKAIYAMA REACTION OF KETENE BIS(TRIMETHYLSILYL)ACETALS WITH α-HALO ACETALS - A CONVENIENT BUTENOLIDE SYNTHESIS
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Ketene bis(trimethylsilyl) acetals were reacted with α-halo acetals giving β-alkoxy-γ-halo acids which were converted to butenolides by reaction with equivalents of base.This constitutes a novel and short butenolide synthesis.
- Demnitz, F. W. J.
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p. 6109 - 6112
(2007/10/02)
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- STEREOCHEMICAL STUDIES-XXVI CONFORMATIONAL EQUILIBRIA OF KETALS OF 2-SUBSTITUTED CYCLOHEXANONES
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The positions of the conformational equilibria in a series of 2-substituted cyclohexanone ketals have been determined by 1H NMR.For the ethylene ketals 6 the equatorial conformer has been found to be enthalpically preferred.The other ketal syst
- Mursakulov, Ismail G.,Guseinov, M. M.,Kasumov, N. K.,Zefirov, Nikolai S.,Samoshin, V. V.,Chalenko, E. G.
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p. 2213 - 2220
(2007/10/02)
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