Albicanyl acetate

Polyene cyclization in terpene and steroid synthesis is critically dependent on the terminator in order to generate useful functionalities for further modification of the products. Allyl- and propargylsilanes have proven their value in facilitation of the cyclization and generation of an exocyclic methylene and allene, respectively. Thus, a concise approach to albicanyl acetate [126] and the rapid construction of a tetracyclic precursor of steroids [127] are sufficient to demonstrate the concept. Again, a comparison of the substrates with a silyl group with those having a simple alkyl moiety is very enlightening. 

In another study C. luteomarginata, collected from two locations (Howe Sound and Barkley Sound) in British Columbia (68), was found to contain albicanyl acetate [79], albicanol [80],... 

Earlier it was indicated (Schemes 5, 7, 10) that the hydroxy acetate (42) was transformed into the drimenol (2) [49], its acetate (12) [42] or a mixture of the drimenol (2) and the albicanol (43) [39]. Authors [55] accomplished the targeted synthesis of the albicanol (43) and its acetate (68) starting with the hydroxy acetate (42) (Scheme 12). The hydroxy acetate (42) was dehydrated with thionyl chloride into the mixture of acetates (12), (67) and (68), which was subjected to oxidation with m-CPBA. On that treatment the acetates (12) and (67) are selectively oxidised, but the acetate (68) remained unreacted. The latter was than isolated by chromatography and saponified into the albicanol (43). The overall yield of the albicanyl acetate (68) and the albicanol (43) was 61% (at the saponification step the yield of (43) was quantitative). Barrero et al. 

It should be mentioned that the albicanyl acetate (68) is a biologically active substance, being a powerful antifeedant for fish [56]. The albicanol... 

Akita, H., Nozawa, M., Mitsuda, A., and Ohsawa, H. (2000) A convenient synthesis of (-l-)-albicanol based on enzymatic function total syntheses of (-l-)-albicanyl acetate, (-)-albicanyl 3,4-dihydroxycinnamate, (-)-drimenol, (-)-drimenin and (-)-ambrox. Tetrahedron Asymmetry, 11,1375-1388. 

Anilkumar, A.T., Sudhrr, U., Joly, S., and Narr, S.M. (2000) Studies in lipase catalyzed trans-esterifications synthesis of (+)-albicanol, (+)-albicanyl acetate and chiral intermediates useful in the synOiesis of drimanes and labdanes. Tetrahedron, 56,1899-1903. 

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