Synthesis in the Diazasteroid Group. XX. Synthesis of the 5, 14-Diazasteroid System

Abstract

trans-2-Quinolizidinone (I) was treated with methyl 2-pyrrolidylacetate (III) to give a mixture of two isomers, 5, 14-diaza-1, 6-cyclo-1, 10-secogon-8-en-11-one (IV) and 5, 14-diazagon-8-en-11-one (Va) in 8.6 and 2.7% yields, respectively. 1, 2, 3, 3a, 4, 5, 6, 7, 8, 9-Decahydro-7-benzoylpyrrolo [1, 2-a]-[1, 6] -naphthyridin-5-one (VIb) [prepared from 1-benzoyl-4-piperidone (IIb) and III] was hydrolyzed and then allowed to react with methyl vinyl ketone to give a Michael adduct (VId). It was treated with mercuric acetate to afford regio-and stereoselectively 5, 14-diazagon-8-ene-2, 11-dione (Vb), whose angular protons at the C₁₀ and C₁₃ were anti to each other. The structure of Vb was determined by X-ray crystallographic analysis. Compound Vb was converted to Va via a thioketal (Vc).