Oxazaborolidine-Catalyzed Enantioselective Reduction of α-Methylene Ketones to Allylic Alcohols
摘要:
Oxazaborolidine-catalyzed enantioselective reduction of a-methylene ketones was efficiently carried out by using borane-diethylaniline as a stoichiometric reducing agent. The combination of this method and subsequent hydrogenation of thus-formed allylic alcohol improved stereoselectivity in the reduction of 24-oxocholesteryl ester to 24-(R)-hydroxycholesteryl ester.
Palladium-Catalyzed Cross-Coupling of Unactivated Alkenes with Acrylates: Application to the Synthesis of the C13-C21 Fragment of Palmerolide A
作者:Zhen-Kang Wen、Yun-He Xu、Teck-Peng Loh
DOI:10.1002/chem.201201806
日期:2012.10.15
Diene to meet: A palladium‐catalyzed cross‐coupling reaction between alkyl‐substitutedolefins and acrylates gives the corresponding butadienes in moderate yield and stereoselectivity. This atom‐economical reaction, which forms C–C bonds, tolerates a wide range of allylic and homoallylic alcohols, and acrylates (see scheme; TIPS =triisopropylsilyl). The methodology was applied to the synthesis of the
Synthesis and reactions of [(allyloxy)methyl]sulfones - an equivalent for the [2,3]-wittig rearrangement of nonconjugated secondary carbanions
作者:Reinhard Brückner、Beate Peiseler
DOI:10.1016/s0040-4039(00)80724-8
日期:1988.1
The title compounds 4 are prepared from allylic alcohols 1 and tosyldiazomethane. Their anions undergo [2,3]-Wittig rearrangements which allow the incorporation of additional carbon atoms into the molecule.