Synthesis of Acenaphthene-1-carboxylic Acid Using Lithiated Tris(methylthio)methane to Carboxylate 1-Bromoacenaphthene
17 September 2002 (online)
A new synthesis of acenaphthene-1-carboxylic acid (4) in 3 steps and 78% overall yield from 1-bromoacenaphthene (1) is described. In the key step, lithiated tris(methylthio)methane is reacted with 1-bromoacenaphthene to give 1-[tris(methylthio)methyl]acenaphthene (2). Methanolysis of 2 gives racemic methyl acenaphthene-1-carboxylate 3, which is resolved by chiral chromatography. The usefulness of tris(methylthio)methyllithium as a carboxyl carbanion equivalent is illustrated by the conversion of three other bromides to the corresponding methoxycarbonyl derivatives.