合成路线1

This compound has been obtained by several related ways: 1.- The Sam and Thompson cyclization of 3-(2-thienyl)acrylic acid (I) gives the thienocyclopentanone (II), which is condensed with oxoacetic acid (III) yielding 2-(4-oxo-5,6-dihydro-4H-cyclopenteno[b]furan-5-ylidene)acetic acid (IV). The reduction of (IV) with Zn and acetic acid affords the corresponding saturated compound (V), which is condensed with 4-(6-fluoro-1,2-benzisoxazol-3-yl)piperidine (VI) by means of DCC and HOBt in dichloromethane to give the corresponding piperidide (VII). The protection of the ketonic group of (VII) with ethylene glycol and TsOH yields the ethylene ketal (VIII), which is reduced at the piperidide group with LiAlH4 in ethyl ether yielding the final intermediate (IX). Finally, this compound is treated with HCl to eliminate the ethylene ketal protecting group. 2.- The condensation of the thienocyclopentanone (II) with ethyl bromoacetate (X) by means of LDA gives the acetate (XI), which is hydrolyzed with KOH in ethanol affording the previously reported saturated acetic acid derivative (V). 3.- The condensation of acetate (XI) with piperidine (VI) by means of Me3Al gives also the previously reported piperidide (VII).