A facile synthesis of chiral ω-allyl- and ω- n-propyllactones via asymmetric allylboration of formyl esters with B-allyldiisopinocampheylborane

Abstract

Asymmetric allylboration of aldehydes containing an adjacent ester group with B-allyldiisopinocampheylborane, followed by hydrolysis and cyclization, provides the corresponding allyl substituted lactones in high yields and ≥92% enantiomeric excess. Hydrogenation of these lactones provides the corresponding propyl substituted lactones without any loss of optical purity.