Method For Preparing Indene Derivatives, And Intermediates For Preparation Of Derivatives

Indene derivatives that are utilizable as intermediates in the synthesis of the vitamin D2 derivative paricalcitol, which is useful as pharmaceutical are efficiently prepared by subjecting a vitamin D2 derivative such as 25-hydroxyvitamin D2 to a two-steps oxidation reaction using an oxidizing agent such as potassium permanganates and sodium periodate in a suitable solvent such as methanol and ethanol.