Enantioselective total synthesis and structure revision of spirodihydrobenzofuranlactam 1. Total synthesis of stachybotrylactam.
[reaction: see text] The enantioselective total synthesis and structure revision of spirodihydrobenzofuranlactam 1 and of its regioisomer 25 are presented. Optically pure (+)-Wieland-Miescher ketone was utilized to construct the AB bicyclic core in 10 steps. Introduction of the resorcylate D-ring unit was achieved by use of our tert-butyl ester metalation sequence. Subsequent stereoselective spirocyclization to form the C-ring was followed by regioselective ring cyanation and lactam formation to produce the pentacyclic structure 1 and its regioisomer 25.
Kende
Andrew S
AS
Department of Chemistry, University of Rochester, Rochester, New York 14627, USA. kende@chem.rochester.edu
Deng
Wei-Ping
WP
Zhong
Min
M
Guo
Xiao-Chuan
XC