Enantiopure Acetals of α-Alkynyl Carbonyl Compounds: Organoaluminum-Mediated 1,2-Shift of Cobalt-Complexed Alkynyl Group with Concomitant Capture by a Nucleophile

Abstract

Upon treatment with the organoaluminum-based combination of Lewis acid and nucleophile, chiral mesyloxy acetal having a Co-complexed alkynyl group undergoes stereospecific 1,2-shift of the complexed alkynyl and the concomitant attack of te ligand R of the organoaluminum reagent. Decomplexation of the products with CAN gives the chiral acetals of α-alkynyl carbonyl compounds in enantiomerically pure form in high yields.