7-substituted derivative of 3,5-dihydroxyhepta-6-ynoic acid and its production

NEW MATERIAL: A compd. represented by formula I {wherein R is a group represented by formula II [wherein R 1 and R 2 are each up to 6C alkyl, alkenyl or a 3-6C cyclic hydrocarbon, X=Y-Z is the formula CR 3 =CR 4 -CR 5 (R 3 -R 5 are each H, up to 6C alkyl or alkenyl) and R 0 is H, up to 6C alkyl, an alkali metal or ammonium}, its deriv. and a lactone corresponding to formula III. EXAMPLE: 6RS-2-(4-(4-fluorophenyl)-2-(1-methylethyl)-6phenylpyridin-3-yl)ethynyl-4 SR-hydroxy-3,4,5,6-tetrahydro-2H-pyran-2-one. USE: A drug for preventing and treating hypercholesterolemia. PROCESS: Aldehyde represented by formula IV is converted to corresponding hydroxyketoester represented by formula V (wherein R 0 is a 1-6C alkyl) and subsequently reacted with triethyl- or methoxydiethylborane and the reaction product is reduced to obtain the compd. represented by formula I. COPYRIGHT: (C)1990,JPO