Functionalization of Lupane-3β,28-diyl Diacetate with Chromium(VI) Oxide. Part 2

Abstract

Oxidation of lupane-3β,28-diyl diacetate (1) with chromium trioxide was reported already earlier to give small amounts of products functionalized in position 19β and 11 (19β-hydroxylupane-3β,28-diyl diacetate (3) and 11-oxolupane-3β,28-diyl diacetate (6)), together with products of subsequent oxidation, 21-oxolup-18-ene-3β,28-diyl diacetate (4) and anhydride (5). Now we identified further products, arising by functionalization in positions 12, 16 and 21 (12-hydroxy-11-oxolup-12-ene-3β,28-diyl diacetate (8), 12-oxolupane-3β,28-diyl diacetate (9), 11-oxolup-12-ene-3β,28-diyl diacetate (17), 21-oxolupane-3β,28-diyl diacetate (20) and 16-oxolupane-3β,28-diyl diacetate (22)), either as such or after conversion into other derivatives. The obtained compounds were further transformed and structure of the prepared derivatives was confirmed by 1H NMR, 13C NMR and mass spectroscopy.