REGIOSELECTIVE OXIRANE RING-OPENING OF TRANS-2,3-EPOXY ALCOHOLS WITH ARYLALUMINUM COMPLEXES

Abstract

Treatment of trans-2,3-epoxy alcohols 1, activated by triethylaluminum, with arylaluminum complexes 3 caused a regioselective ring-opening reaction at the 3-position to yield 3-aryl-1,2-alkanediols 4 in moderate yields. The activation of the epoxY ring by coordination with a Lewis acid appears to be essential for obtaining the desired product in a reasonable yield. While bulky substituents at the 3-position lowered the regioselectivity, a methoxy or methylenedioxy moiety on the arylaluminum complex 3 improved the regioselectivity drastically.