Organocatalytic Approach for Short Asymmetric Synthesis of ( R)-Paraconyl Alcohol: Application to the Total Syntheses of IM-2, SCB2, and A-Factor γ-Butyrolactone Autoregulators.

( R)-Paraconyl alcohol is found to be a key intermediate for the syntheses of many γ-butyrolactone autoregulators. The chiral auxiliary approach and enzymatic resolution are the two common strategies employed so far in the literature for the asymmetric synthesis of ( R)-paraconyl alcohol. Herein, we report the first organocatalytic approach for the short asymmetric synthesis of ( R)-paraconyl alcohol in four steps and by a single column purification. Asymmetric syntheses of IM-2, SCB2, and A-factor γ-butyrolactone autoregulators were achieved from ( R)-paraconyl alcohol in three steps.