Industrial Technology Research Institute

Yung Shin Pharmaceutical Ind. Co., Ltd.

Yeuk-Chuen Liu

Yuh-Lin Allen Yang

An acylation process using a sulfonic acid, a salt of the sulfonic acid, or a mixture thereof, as a catalyst. Compound 6 is prepared by protecting the 4-hydroxyl group on the pyranone ring of the 8'-hydroxy compound 2 to form a .beta.-protected compound 3, acylating the 8-hydroxy group on the polyhydronaphthyl ring of compound 3 to give protected ester, compound 4, then removing the protecting group, where the compounds 6, 2, 3 and 4 are as described in the specification.

Process for preparing

The process for preparing compound 2 by reacting the compound 1, each as described in the specification hereof, with a tetraalkyl ammonium hydroxide having the formula R.sub.1 R.sub.2 R.sub.3 R.sub.4 N.sup.+ OH.sup.-, wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are each independently a C.sub.1 -C.sub.10 alkyl group or a (C.sub.6 -C.sub.10) aryl (C.sub.1 -C.sub.10) alkyl group, to obtain an triol carboxylate thereof, acidifying the triol carboxylate, then lactonizing the product to obtain diol lactone, a key intermediate for production of antihypercholesterolemia agents.

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Hsinchu, Taiwan

Yeuk-Chuen Liu