Stereoselective Total Synthesis of (-)-(6R,11R,14R)-Colletallol via RCM Protocol
作者:Palakodety Krishna、D. Ramana、B. Reddy
DOI:10.1055/s-0029-1218270
日期:2009.11
The totalsynthesis of (-)-colletallol via a ring-closing metathesis protocol is reported. (-)-colletallol - ring-closing metathesis (RCM) - Grubbs II catalyst - Jacobsen’s hydrolytic kinetic resolution (HKR)
Lithium enolates generated from t-butyl esters of δ-hydroxy carboxylic acids with lithium dialkylamides in THF–HMPA were alkylated stereoselectively to give the corresponding syn-α-alkylated δ-hydroxy esters. The generation of the enolates was accelerated by the addition of lithium trifluoromethanesulfonate, and the successive aldol and hydroxylation reactions of the enolates also proceeded in a stereoselective manner.