Filipin III: Configuration Assignment and Confirmation by Synthetic Correlation
作者:Timothy I. Richardson、Scott D. Rychnovsky
DOI:10.1021/jo960218x
日期:1996.1.1
The stereochemical configuration of filipinIII (1) was determined using the (13)C acetonide analysis. The relative configurations for the nine stereogenic centers in the top half of filipin were initially identified using just three acetonide derivatives (2, 3, and 4) arising from a two-step protection sequence. The structure was confirmed by synthesis and direct correlation of degradation products
Prompt Determination of Absolute Configuration for Epoxy Alcohols via Exciton Chirality Protocol
作者:Xiaoyong Li、Babak Borhan
DOI:10.1021/ja805058t
日期:2008.12.3
A microscale protocol for determination of absoluteconfigurations of 2,3-epoxy alcohols is described. 2,3-Disubstituted (cis and trans), 2,2-disubstituted, 2,2,3-trisubstituted, and 2,3,3-trisubstituted epoxy alcohols rendered prominent ECCD signals upon complexing with a Lewis acidic porphyrin tweezer and consequently provide straightforward assignment of chirality for epoxy alcohols. This method
Asymmetric Synthesis of (2<i>R</i>,3<i>S</i>)-2,3-Epoxyoctanal, a Key Intermediate of 14,15-Leukotriene A<sub>4</sub>
作者:Sadao Tsuboi、Hiroyuki Furutani、Akira Takeda
DOI:10.1246/bcsj.60.833
日期:1987.2
Asymmetric reduction of ethyl 3-chloro-2-oxooctanoate with baker’s yeast gave ethyl 3-chloro-2-hydroxyoctanoate (3) [(2S,3R)/(2S,3S), 4:1] in 67% yield with >99% e.e. Chlorohydrin (2S,3R)-3 was converted to the titled compound in 34% total yield with 80% e.e. via the reduction, dehydrochlorination, and oxidation, successively. (2R,3R)2,3-Epoxyoctanal was also prepared from (2S,3S)-3 in 33% total yield
Tungsten-Catalyzed Regioselective and Stereospecific Ring Opening of 2,3-Epoxy Alcohols and 2,3-Epoxy Sulfonamides
作者:Chuan Wang、Hisashi Yamamoto
DOI:10.1021/ja5029809
日期:2014.5.14
The first catalytic, highly C3-selective, stereosepecific ring-opening reaction of 2,3-epoxy alcohols and 2,3-epoxy sulfonamides has been accomplished. This process was efficiently promoted by W-salts, and the developed method was applicable to various epoxides with diverse N- and O-nucleophiles affording the products in good to excellent yields (up to 95%) and generally with high regioselectivities (C3:C2 up to >99:1).