Reduction of Some Vinylogous Esters with Lithium Aluminum Hydride. V

Abstract

With excess lithium aluminum hydride, 2-methyl-3-methoxy-2-cyclopentenone (III), 2-ethyl-3-methoxy-2-cyclopentenone (IV), and 2, 5-dimethyl-3-methoxy-2-cyclopentenone (VI) were reduced to the corresponding allyl alcohols, 2-methyl-2-cyclopentenol (Xa), 2-ethyl-2-cyclopentenol (XIa), and 2, 5-dimethyl-2-cyclopentenol (XIIa), respectively. On the other hand, 2, 4-dimethyl-3-methoxy-2-cyclopentenone (V) was reduced to 2, 4-dimethyl-2-cyclopentenol (XIVa), 2, 5-dimethyl-2-cyclopentenone (XIII_(v)e), and 2, 4-dimethyl-3-methoxy-2-cyclopenteno1-(XVc). Mechanism if this reduction and the substituent effect are described.