Selective Oxidation of Betulin for the Preparation of Betulinic Acid, an Antitumoral Compound

Abstract

This paper describes a semisynthetic approach for the preparation of betulinic acid from betulin. The main step of this synthetic approach is the selective oxidation of primary alcohol function of betulin. This reaction is accomplished with chromic oxide adsorbed on silica gel to obtain betulinal in an adequate yield. Betulinal is then almost quantitatively oxidized to betulinic acid by potassium permanganate action.

Keywords:

• Betulinic acid
• Chromium oxide
• Oxidation
• Solid supported reagent

Acknowledgments

This project was supported by Fonds Québécois de la Recherche sur la Nature et les Technologies (Fonds Forestiers), Scierie Thomas‐Louis Tremblay, and Clinique des Lipides du Complexe Hospitalier de la Sagamie. We are also grateful to Prof. François‐Xavier Garneau for his scientific advices and discussions.