Synthesis of vitamin C from pectic substances

Abstract

A new process for the preparation of vitamin C from beet pulp and other pectic substances has been developed. The pectic substance is treated with a pectinase, the resulting galacturonic acid is separated in the form of a difficultly soluble salt which is reduced with hydrogen to a salt of L-galactonic acid. The salt is converted to L-galactono-lactone and oxidi zed to 2-keto-L-galactonic acid, which is lactonized and enolized to yield ascorbic acid (vitamin C). Electronic interpretations are presented for the conversion of methyl 2-keto-L-galactonate to ascorbic acid by basic catalysts, for the lactonization and enolization of 2-keto-hexonic acids by acid catalysts, and for the formation of furfural and reductic acid from pentoses, galacturonic acid, and ascorbic acid. CONTENTS 1. Lactonization and enolization of methyl 2-keto-L-galactonate by sodium methylate____ ___ _ ___ __ __ ___ ___ __ __ _ _ _ _ _ _ __ __ __ __ 55 2. Lactonization and enolization of 2-keto-hexonic acids by the action of acid catalysts_________________________ ____ _____ 56 3. Formation of furfural and reductic acid from pentoses, galacturonic acid, and ascorbic acid_ _ _ _ _