Highly stereoselective preparation of β-(organotelluro)acroleins and facile stereospecific synthesis of conjugated dienols

Diorganoditellurides 1 (1a R = n-Bu;1b R = Ph), by treated with sodium borohydride, reacted with propargylaldehyde to give corresponding β-(organotelluro)acroleins 2 with high (Z)-stereoselectivity in good yields (2a: Z:E = 89:11; 2b: pure Z-isomer); Tellurides 3, on treatment with n-BuLi, reacted with carbonyl compounds to afford conjugated dienols with retention of olefin geometry in high yields.