Regio and stereospecific ring expansion of optically active cyclopropylvinylcarbinols. Diastereoselective synthesis of cis Quercus- lactone b.
作者:Jacques Salaun、Belkacem Karkour
DOI:10.1016/s0040-4039(00)80345-7
日期:——
(-)-(S) dimethyl α-methylsuccinate, from enzymatic resolution, underwent acyloin cyclization followed by stereospecific C4→ C3 ring contraction to provide chiral cyclopropylvinylcarbinols. Then, BF3-Et2O induced regio- and stereospecific C3 → C4 ringexpansion led to optically active cyclobutanones precursors of cis γ-lactones, with high enantiomeric excesses.