Epoxidation of indene by chloroperoxidase

The stereochemistry of the chloroperoxidase-catalyzed epoxidation of indene has been elucidated. In aqueous solution the intial epoxide product is not stable and opens to form the cis-trans diols. When the reaction was carried out in the absence of water, the epoxide enantiomers could be isolated. Under these conditions in 1R2S enantiomer was formed in approximately 30% ee.