Novel rearrangement of an isocaryolane sesquiterpenoid under mitsunobu conditions

Under modified Mitsunobu reaction conditions, a novel skeleton rearrangement of terpenes has been obtained. The reactivity of 8, 9-dioxygenated isocaryolane derivatives has been investigated. When either (8R,9R)-8-methoxyisocaryolane-9-ol (7) or (8R, 9R)-isocaryolane-8,9-diol (10) are treated under acidic conditions, isocaryolan-9-one (9) and the rearrangement compound (1S,2S,5R,8S)-1, 4,4-trimethyltricyclo[6.2.1.0(2,5)]undecane-8-carbaldehyde (11) are obtained. Otherwise treatment of compounds 7 and 10 under modified Mitsunobu conditions leads to the novel sesquiterpene derivative (1S, 2S,5R,9R)-1,4,4-trimethyltricyclo[7.2.1.0(2,5)]dodecan-8-one (8). This is the first example, to our knowledge, of a Mitsunobu-induced pinacol rearrangement. The influences of the substrate and reaction conditions on the evolution of the reaction are both explored. This modification of the Mitsunobu reaction conditions introduces a new, one-pot, procedure for preparing this class of rearrangement product.

Biotransformation of the fungistatic sesquiterpenoid patchoulol by botrytis cinerea

Biotransformation of the fungistatic sesquiterpenoid patchoulol (1) by the fungus Botrytis cinerea affords the 5-, 7- and (8R)-hydroxy (2, 3, and 5) derivatives as the major metabolites, together with a number of minor metabolites (4, 6-9) arising from hydroxylation at C-2, C-3, C-5, C-9, C-13, and C-14.

Biotransformation of caryophyllene oxide by botrytis cinerea

Biotransformation of caryophyllene oxide (1) with B. cinerea afforded 15 products (2-16). Ten of these (3-5, 7, 9-11, and 14-16) are reported here for the first time. The main reaction paths involved stereoselective epoxidation at C-8/C-13 and hydroxylation at C-7. A rearranged compound was found, which was a cyclization product 16 possessing the caryolane skeleton.

The biotransformation of some clovanes by botrytis cinerea

The metabolism of the fungistatic agent 2beta-methoxyclovan-9alpha-ol (2) by the fungus Botrytis cinerea has been investigated. Biotransformation of compound 2 yielded compounds 3-5, 7, and 9. The major metabolites of compound 2 each show much reduced biological activity when compared with the parent compound. Also studied were the effects of B. cinerea on the metabolism of the related compounds 2beta-methoxyclovan-9-one (3), 2beta-methoxyclovan-9beta-ol (4), and clovan-2,9-dione (6). Compounds 3, 4, 8, and 9 are described for the first time.