To provide a method for industrially producing an indene derivative useful as an intermediate for synthesizing vitamin D derivatives in relatively few steps, to provide intermediates of the indene derivative and a method for producing the intermediates.
The method for producing the indene derivative comprises the steps of reacting a cyclohexadienecarbonyl derivative of the general formula (I) with a trifluoromethanesulfonic acid derivative to form a triene derivative of the general formula (II), subjecting the triene derivative to a palladium catalyst to form an indanediene derivative of the general formula (III), and then reducing the indanediene derivative in the presence of a catalyst to obtain the objective indene derivative of the general formula (IV). In the above formulae, the respective signs are the same as defined in the Specification.
