A Synthesis of exo-3-Formyl-3-methylcamphor

Abstract

exo-3-Formyl-3-methylcamphor was synthesized by a following route, for the purpose of asymmetric alkylation of glycine. Methyl 3-methyl-3-eamphorcarboxylates [4] were obtained by the methylation of methyl 3-camphorcarboxylate [3]. with sodium hydride and methyl iodide in good yield. The products were separated into two parts by treating with ligroine, i.e. a crystalline part [4a] (mp 88~88. 5°C) and an oily one [4 b], It was found that the structure of [4 a] was determined as exo-3-earboxylate and that of [4 b] was as endo-one by the analyses of their NMR data. The reduction of [4 a] with LiAlH4 gave diol [5]. And exo-3-formyl-3-methylcamphor was obtained as a slightly unstable liquid (bp 123°C/13 mmHg, [α]20D -162. 5°) by the oxidation of [5]) with Collins' reagent. © 1987, The Chemical Society of Japan. All rights reserved.