Birch reduction of 2-Methoxy-1-naphthoic acids

Abstract

The reduction of 2-methoxy-1-naphthoic acids (1) with 2.4 equiv. of sodium in liquid ammonia leads to the formation of the 1,4-dihydro compounds (2). These reduction products on esterification with diazomethane followed by hydrolysis with dilute mineral acids yield methyl 2-oxotetralin-1-carboxylates (5). This constitutes a satisfactory general method of synthesis of (5).