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A convenient synthesis of drimenol by treatment of readily available drimane 8α,11 diol 11 monoacetate with sulfuric acid in ethanol under mild conditions was developed. Oxidation of drimenol with selenium dioxide gives known drim 7 ene 9α,11 diol and drim 7 ene 11,12 diol as the major products.

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A Short Efficient Synthesis of 11-Monoacetate of Drimane-8α,11-diol from Norambreinolide.-Opening of the lactone ring of norambreinolide (I) with MeLi followed by Baeyer-Villiger oxidation of the resulting hydroxyketone (III) provides an efficient two-step synthesis of drimanediol monoacetate (V). -(KUCHKOVA, K. I.; CHUMAKOV, YU. M.; SIMONOV, YU. A.; BOCELLI, G.; PANASENKO, A.

Nitrogen-containing drimanes and their biological activity represent a poorly studied area of terpenoid chemistry. Therefore, the synthesis of such compounds is of scientific interest.The preparation of amides 1-4 via Beckmann rearrangement of the Z-and E-isomers of oxime 5 of 14,15-dinorlabd-8(17)-en-13-one (6) was reported earlier [1]. A multi-step synthesis of amide 7 from (-)-sclareol that uses the natural sesquiterpene drim-9,11-en-8D-ol (8) as an intermediate in the synthesis was described [2].Our goal was to study the synthesis of 7 via Beckmann rearrangement of oxime 9 of 11-dihomodriman-8D-ol-12-one (10). Hydroxyketone 10 is readily available and can be obtained from norambreinolide (11) by the method described by us [3]. Oxime 9 was prepared from 10 by reaction with NH 2 OHHCl in a mixture of EtOH and Py. It was a mixture of the Z-and E-isomers according to TLC and 1 H, 13 C, and 15 N NMR spectra. Because the Z-isomer can be easily converted to the E-isomer and the latter is energetically more favorable [1, 4], we used 9 for the reactions as a mixture of its Z-and E-isomers. The Beckmann rearrangement is known to occur stereospecifically as a result of anti-migration of the bulkier radical. Therefore, it was expected that the major product of the Beckmann rearrangement of 9 would be amide 7.

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An efficient one step synthesis of the diacetate of the tetracyclic triterpenoid onoceranediol (4) by radical cleavage of the readily available 12 hydroperoxy 8α,12 epoxy 11 bishomo drimane is described. Drim 9(11) en 8α yl acetate (7) is formed in this reaction as a by product. Onoceranediol diacetate 4 is converted into onoceranediol on treatment with LiAlH 4 , and acetate 7 is transformed into drim 9(11) en 8α ol on saponification.