The ring-contraction of the enedioneepoxide obtained from the adduct of benzoquinone and cyclopentadiene is mainly affected by the amount of base used. Excellent yields (>80%) of the ring-contracted product were consistently obtained when the epoxide was treated with a 0.5 equiv. of ethanolic sodium hydroxide in ethanol. The versatility of the chiral building block accessible from the ring-contracted
Racemic 3-hydroxy-2-hydroxymethyl-endo-tricyclo[5.2.1.0(2,6)]-dec-4,8-diene serving as a synthetic equivalent of 2-hydroxymethylcyclopentadien-5-ol has been resolved by employing lipase-mediated kinetic transesterification with vinyl acetate in an organic solvent. (C) 1998 Elsevier Science Ltd. All rights reserved.