L. Dolby, S. Sakai
1967
Citations
0
Influential Citations
6
Citations
Journal
Tetrahedron
Abstract
Abstract Two methods are described for the preparation of 3,4- seco -dihydrocorynantheine derivatives bearing an oxygen function at C-3. The first is the cyclization by Ac 2 O-AcONa of dihydrocorynantheic acid and its derivative lacking the methoxymethylene group. This cyclization yields acetoxylactams in which lactam formation has taken place between N b and the carboxyl group accompanied by cleavage of the C-3 N b bond with the introduction of an acetoxy group at C-3. The structures of the lactams are supported by spectroscopic evidence and degradative studies. The second method required 7-acetoxy-7H-dihydrocorynantheine methiodide prepared by treating dihydrocorynantheine successively with lead tetraacetate and methyl iodide. 7-Acetoxy-7H-dihydrocorynantheine-N b -methiodide is converted by the action of hot aqueous acetic acid-sodium acetate and extraction from strongly basic solution to 3-keto-3,4- seco -N b -methyldihydrocorynantheine. Dihydroburnamicine was obtained by a three-step sequence from 3-keto-3,4- seco -N x -methyldihydrocorynantheine and its mass spectrum is reported.