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Planta Med 1971; 20(5): 244-252
DOI: 10.1055/s-0028-1099700
© Georg Thieme Verlag Stuttgart · New York

CHEMISTRY OF URSOLIC ACID

T. Mezzetti, G. Orzalesi, V. Bellavita
  • Perugia – Istituto di Chimica Farmaceutica e Tossicologica dell' Università
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Publication History

Publication Date:
15 January 2009 (online)

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Abstract

Oxidation of ursolic acid acetate with chromium trioxide in acetic acid leads to 3β–acetoxy–11–oxoursolic acid (50 %) and a new ketolactone, 3β–acetoxy–12–oxo–ursan–28–oic–13(28)–lactone (20 %) if the reaction temperature is kept under 80° C. At 100° C, 3β–acetoxy–11,12–dioxoursan–28–oic–13(28)lactone (26 %) is formed instead of the 12–oxo–lactone.

LiAlH4 reduction of 3β–acetoxy–11–oxo–ursolic acid yields two new compounds, 3β–ol–ursa–11,12–ene–13,28–oxaand3β–ol–ursa–11,12–ene–13(28)–lactone.

The reduction mechanism is investigated and described.

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