Chemistry of the Podocarpaceae. XXXIV. Some oxidation products of (13R)-Labda-8(17),14-dien-13-ol (Manool)

Abstract

Some products from the oxidation of manool (3) are examined. Potassium permanganate gives, inter alia, the hitherto unreported compound (16) while sodium dichromate gives the methyl ketone (5) and, as the major product, a mixture of (Z)- and (E)-α,β-unsaturated aldehydes (21). Hypoiodite oxidation of the methyl ketone (5) gives the α-hydroxy acid (26) in addition to the expected acid (6). Products of nucleophilic substitution have also been obtained from the hypoiodite oxidation of the methyl ketones (9) and (37). Peracid oxidation of the methyl ketone (5) gives the epoxy acetate (41) which, on reduction with lithium aluminium hydride, affords the diol (7), from which the odoriferous oxide (30) can be prepared. Oxidations leading to formation of the dione (10) are investigated.