To obtain the subject compound simply and highly stereoselectively, useful as a synthetic intermediate for CD ring part in the synthesis of 1α, 24- dihydroxyvitamin D3 effective as a medicine.
This indene compound expressed by formula I (R is H, a 2-8C acyl, etc.; A, B are each H or a C-C bond by A and B, etc.; * shows isomers originated from an asymmetric carbon present with a deviation to one of the isomers) is obtained by reacting a compound expressed by formula II with 2-nitro propane in the presence of a double nuclear catalyst constituted by (R) or (S)-binaphthol derivative expressed by formula III {R1 is H, trimethylsilylethinyl, etc.; Ln is lanthanum or samarium} as an asymmetric source to obtain a nitroaldol compound expressed by formula IV, and removing nitro group thereof by reacting with a hydrogenated tributyltin in the presence of a radical initiator.
OSHIDA JUNICHI
TANAKA TOSHIO
