HIGHLY REGIOSELECTIVE AND STEREOSELECTIVE RADICAL ADDITION OFp-TsBr TO α-ALLENIC ALCOHOLS AND THEIR ELIMINATION REACTION: SYNTHESIS OF β-p-TOSYL-SUBSTITUTED α,β-UNSATURATED KETONES

Regio- and stereoselective radical addition of α-allenic alcohols with p-TsBr in the presence of a catalytic amount of AIBN afforded (E)-γ-bromo-β-sulfonyl allylic alcohols in moderate yields. The base-promoted 1,4-elimination followed by isomerization to give β-sulfonyl-α,β-unsaturated ketones is described.