| 摘要 |
PROBLEM TO BE SOLVED: To efficiently produce the subject compound useful as a synthetic intermediate, etc., for a blood cholesterol lowering agent by reacting a specific aldehyde with a diketene in the presence of a Ti or an Al compound and an optically active Schiff base. SOLUTION: An aldehyde represented by formula I (R<1> is silyl) (e.g. trimethylsilyl-2-popynal) is reacted with a diketene represented by formula II in the presence of a metallic compound, comprising titanium or aluminum and having at least one group represented by the formula OR<2a> [R<2a> us a (substitutes) hydrocarbon] (e.g. titanium tetraisopropoxide) and an optically active Schiff base represented by formula III (R<3> to R<8> are each an alkyl, an aryl, etc.; R<9> is H, an alkyl, an aryl, an alkyloxy, an aryloxy, a halogen, nitro, cyano, etc.; (k) is 1-3] or a complex compound of the metallic compound with the Schiff base to afford an optically active 5-hydroxy-3-oxo-6-heptynoic acid ester derivative represented by formula IV. |
