Stereospecific approach to 3-oxocen-7-ones via aliphatic claisen rearrangement. synthesis of (+)-(2R,8S)- and (+)-(2R,8J)-lauthisan
作者:Leo A. Paquette、Thomas J. Sweeney
DOI:10.1016/s0040-4020(01)85577-0
日期:1990.1
A general synthetic strategy based upon thermally-induced Claisen ring expansion as the pivotal step allows for rapid elaboration of the lauthisans in enantiomerically pure condition and proper absolute configuration. The short sequence (nine steps) constitutes a new and versatile route to naturally occurring medium-ring ethers.
Medium Ring Ethers by Ring Expansion−Ring Contraction: Synthesis of Lauthisan
作者:Mark J. Coster、James J. De Voss
DOI:10.1021/ol0262946
日期:2002.9.1
[reaction: see text] A new general method for the construction of medium ring ethers has been developed. This involves the ringexpansion of halo-O,S-acetals followed by a Ramburg-Bäcklund ring contraction reaction with concomitant extrusion of the sulfur atom. This methodology has been utilized for the synthesis of cis- and trans-lauthisan.