Intermediates in the Synthesis of (+)-Grandisol. I

In both (2R,3S)-3-(2-methoxyethyl)-3-methyl-2-(phenylsulfonyl)cyclopentanone, C₁₅H₂₀O₄S, (1), (1S,2R,3S,5R)-2,5-dimethyl-1-(phenylsulfonyl)bicyclo[3.2.0]heptan-2,3-diol, C₁₅H₂₀O₄S, (2), the five-membered ring is in an envelope conformation. In compound (1), the phenylsulfonyl and the methyl groups are cis to each other and the cyclization to the bicycloheptane, (2), occurs with retention of this geometry. The hydroxyl groups in (2) are trans to each other.

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