Studies on the syntheses of heterocyclic compounds. Part 796. A new synthesis of isochroman-3-ones from benzocyclobutenes; an application to a total synthesis of sendaverine

Abstract

Thermolysis of the methoxylated benzocyclobutene-1-carboxylic acids (1) and (2) forms the isochroman-3-ones (9) and (10); compound (10) has been converted into the isoquinoline alkaloid sendaverine (20)via the N-(4-methoxybenzyl)-2-hydroxymethylphenylacetamide (17) and the N-(4-methoxybenzyl)-2-hydroxymethylphenethylamine (18).