Asymmetric Aldol Reaction with Diisopinocampheyl Enolborinates of Propionates

A convenient and general, reagent-controlled, diastereo- and enantioselective aldol reaction of diisopinocampheylboron enolates of esters, followed by reduction, has been developed as an alternative to crotylboration-ozonolysis. This protocol was then exploited for the double diastereoselective synthesis of the C11-C17 subunit of (-)-dictyostatin.