Synthetic Approaches to Calycanthaceae Alkaloids. III. Reductive Cyclization of 3, 3'-Bioxindoles. (1). A Formation of 5, 7-Dimethyl-11b, 11c-bis (2-dimethylaminoethyl)-5, 5a, 6a, 7, 11b, 11c-hexahydrofuro [2, 3-b : 5, 4-b'] diindole.

抄録

The Ladenburg reduction and lithium aluminium hydride reduction of 3, 3'-disubstituted 3, 3'-bioxindole were carried out. By the former method, (I) and (II) gave 1, 3-dimethylindole and 1-methyl-3-(2-aminoethyl) indole respectively, while by the latter method, (I) gave furo [2, 3-b : 5, 4-b'] diindoles (XVIII, XXV). The compound (XXVII), which has the same planar structure as the product (XIX) obtained from folicanthine, was obtained by the lithium aluminium hydride reduction of (III).