A new synthesis of (+)-6a-carbaprostaglandin I2 employing yeast reduction of a β-keto ester derived from cis-bicyclo [3.3. 0] octane-3, 7-dione as the key-step
(+)-6a-Carbaprostaglandin I2,(carbacyclin), a stable mimic of prostaglandin I2,(prostacyclin), was synthesized by utilizing the kinetic resolution of (±)-2-ethoxycarbonyl-7, 7- ethylenedioxcybicyclo [3.3. 0) octan-3-one in the course of its yeast reduction as the simple and key reaolution step.