To produce the subject compound useful as a synthetic intermediate of vitamin D3 derivative under mild conditions in high stereo selectivity at a low cost on an industrial scale by producing an octadiene derivative using a heptenone derivative as a starting material and subjecting the octadiene derivative to a cyclization reaction in the presence of a palladium catalyst.
The objective compound expressed by formula IV (R11 is carboxyl, etc.) is obtained by reacting a heptenone derivative of formula I (R1, R2, R3 and R4 are each H, etc.; R5 is OH or an alkoxy) with malonic acid, its ester, its salt, etc., to obtain a nonanediketone derivative of formula II (R8 is OH or alkoxy), further reacting the obtained nonanediketone derivative with a trifluoromethanesulfonic acid derivative, optionally reducing the product to obtain an octadiene derivative of formula III (R9 is a carboxyl, etc.; R10 is trifluoromethanesulfonyl), and subjecting the obtained octadiene derivative to a cyclization reaction in the presence of a palladium catalyst.
NAKAZAWA MAKOTO
