Gallium-Mediated Allyl Transfer from Bulky Homoallylic Alcohol to Aldehydes via Retro-allylation: Stereoselective Synthesis of Both <i>e</i><i>rythro</i>- and <i>t</i><i>hreo</i>-Homoallylic Alcohols¹

Abstract

Retro-allylation of bulky gallium homoallylic alkoxides occurs to generate (Z)- and (E)-crotylgallium reagents stereospecifically, starting from erythro- and threo-homoallylic alcohols, respectively. The (Z)- and (E)-crotylgallium reagents immediately reacted with aromatic aldehydes to afford the corresponding erythro- and threo-homoallylic alcohols, respectively. [reaction: see text]