[摘要]：The synthesis of functionalized pentalene derivs. is described. Bicyclo[3.3.0]octane-3,7-dione (Weiss diketone) was converted in 6 steps into a silyl-protected 3-methylbicyclo[3.3.0]octenol, which was submitted to Lewis acid-catalyzed carbonyl-ene reactions with trioxane yielding the primary alc. I (n = 1) with exocyclic double bond in high yield. By subsequent kinetic resoln. with lipase, I (n = 1) was enantiomerically enriched (?4% ee). Compd. I (R = OH) could be functionalized by hydroboration and oxidative workup to give the trihydroxy pentalene II as well as by chain extension to the pentalene I (n = 2).
