STEREOSELECTIVE TRANSFORMATION OF 2,4-ALKADIENOIC ESTERS TO THE 3,5-DIENOIC ISOMERS WITH LITHIUM DIISOPROPYLAMIDE (LDA)

Treatment of 2(E),4(Z)-alkadienoic esters with lithium diisopropylamide (LDA) at −80 °C gave 3(E),5(E)-isomers with 81–98% stereoselectivity. In contrast, treatment of 2(E),4(E)-isomers with LDA gave 3(E),5(z)-isomers with 72–80% stereoselectivity.