A Highly Stereoselective Synthesis of rel[1R, 3R, 7R, 9S]9-Acetoxy-8, 8-dimethyltricyclo[5.4.0.0^{1, 3}]undecan-4-one, a Versatile Intermediate to Terpenoids. Synthesis of α-Onocerin

抄録

Hydrogenation of the tricyclic acetal 4, which was prepared from the octalone 3 by 2 steps, yielded the trans-dihydro product 5 with high stereoselectivity, while hydrogenation of the dimethyloctalones, 8 and 9, showed low stereoselectivity. 5 was converted to the cyclopropy-decalone 2 in high yield. Reductive alkylation of 2 gave regioselectively the C₁ alkylated trimethyldecalone 12, which was converted to the key intermediate to α-onocerin 16, thus illustrating potential utility of 2 in terpenoid synthesis.