NEW MATERIAL:A compound expressed by formula I (R1WR3 represent aryo, aralkyl or alkyl; R4 and R5 represent protecting group of hydroxyl or H).

EXAMPLE: [3-Formyl-4-phenyldimethylisilyl-7-exo-t-butyldimethylsilyloxymethyl-8- endo-tetrahydropyranyloxy-cis-bicyclo[4.3.0]non-2-enl.

USE: A preventive or remedial agent for cerebral thrombosis, myocardial infarction and acute stenocardia.

PREPARATION: For example, lactol derivative expressed by formula II is subjected to the Wittig reaction to form an α,β-unsaturated ester expressed by formula III (Me represents methyl), which is oxidized to form a cyclopentanone derivative, followed by methylation and trialkylsilylation. Then the product is subjected to oxidation and hydrolysis to form a diol derwative expressed by formula IV and finally subjected to oxidation followed by aldol condensation with dehydration to afford the compound expressed by formula I.