Stereocontrolled Synthesis of Bicyclic Lactone Derivatives via Tungsten-Mediated [3 + 2] Cycloaddition of Epoxides with a Tethered Alkynyl Group
作者:Reniguntala J. Madhushaw、Chien-Le Li、Haw-Lih Su、Chu-Chen Hu、Shie-Fu Lush、Rai-Shung Liu
DOI:10.1021/jo020669j
日期:2003.3.1
works for both cis- and trans-epoxides and tolerates various functional groups. In the case of trans-phenyl epoxide, the reaction led to an addition product via a 6-endo attack of epoxide by the tungsten fragment. This method provides a simple enantiospecific synthesis of complex bicyclic lactones if a chiral epoxide is used in the cyclization. It is also applicable to the one-pot synthesis of bicyclic
Gold-catalysed generation of diol equivalents from epoxides and their intramolecular reaction with C≡C bonds to generate bicyclicketals is presented. This reaction essentially involves the formation of an acetonide, which subsequently cyclises on the alkyne intramolecularly under gold catalysis conditions. This method could be extended to make optically pure bicyclicketals. Deuterium incorporation