Ochotensine and related compounds. II. A synthesis of iso-ochotensine. (Studies on the syntheses of heterocyclic compounds. CCLXXV )

In order to examine the total syntheses of ochotensine (1) and ochotensimine (II), one of the isomers, iso-ochotensine (III), was synthesized as a preliminary experiment. Namely, Wittig reaction of VI, followed by treatment with sodium bicarbonate solution, gave the expected compound, 7-ethoxycarbonyl-3-ethoxycarbonyloxy-2-methoxy-13-methyIene-10,11-methyIene-dioxyochotensinan (VII) which was reduced with lithium aluminum hydride to give III. This was also obtained by methylation of 3-hydroxy-2-methoxy-13-methylene-10,11-methyIenedioxy-ochotensinan (VIII).