Selected regiocontrolled transformations applied to the synthesis of (1S)-cis-chrysanthemic acid from (1S)-3,4-epoxy-2,2,5,5-tetramethylcyclohexanol
作者:Alain Krief、Humaira Y. Gondal、Adrian Kremer
DOI:10.1039/b808695h
日期:——
(1S)-cis-Chrysanthemic acid has been prepared in a few steps with complete control of the relative and absolute stereochemistry using regiocontrolled epoxide ring opening, diol mono-oxidation and cyclopropanation.
Competing cyclopropane over epoxide formation from γ-halogeno-δ-hydroxy-ketones
作者:Alain Krief、Adrian Kremer
DOI:10.1016/j.tetlet.2010.02.003
日期:2010.4
Carbocyclization has been selectively achieved over epoxide formationfrom a γ-chloro-δ-hydroxy-ketone in the presence of a lithiumamide or using a different strategy in which the related silyloxyenol ether bearing an iodine atom at gamma-position and a silyloxy group in delta-position is reacted with tetrabutylammonium fluoride. These approaches take advantage of (i) the poor reactivity of the intermediate