INTRODUCTION OF A FUNCTIONALIZED CARBON CHAIN AT THE 3-POSITION OF 4-METHOXY-2-QUINOLONES VIA PHOTOCHEMICAL 2+2 CYCLOADDITION TO ALKYNES AND THE SYNTHESIS OF (±)-EDULININE

Abstract

Irradiation of 4-methoxy-2-quinolone or its derivatives in methanol in the presence of mono-substituted ethyne gave the head-to-tail adducts : 1-substituted 2a, 8b-dihydrocyclobuta [c] quinolin-3 (4H)-one derivatives. A method for fissioning the C₁-C_8b bond in the adducts was developed. Based on these findings, the cycloadduct obtained from 4-methoxy-1-methyl-2-quinolone and 2-methyl-3-butyn-2-ol was transformed to (±)-edulinine.