The title compounds are representative members of sesquiterpenoid phytoalexins isolated from diseased Solanceae plants. These compounds are characterized structurally by the presence of five or six asymmetric centers in two ten-carbon skeletons, spiro[4,5]decane and perhydronaphthalene, as well as by different stereochemistry at C-4 and C-5 from natural usual sesquiterpenes. We describe herein stereoselective syntheses of these compounds. The process leading to the synthesis of oxygenated spirovetivanes (2〜5) consists of two major steps; (i) synthesis of norsolavetivone (8) starting from orcinol dimethyl ether (9) (Scheme 1) and (ii) regio- and stereoselective introduction of nucleophile(s) into C-10 followed by conversion into lubimin (2) and related compounds and (3 and 21) (Scheme 3). Transformation into oxylubimin (3) from 8 essentially in the same manner is under investigation. On the other hand, the process aimed at the synthesis of capsidiol (6) is summarized in Scheme 6, resulting in preparation of epoxy diene (24). Transformation of 24 into 2 by π-cyclization is also under investigation.
