ChemInform Abstract: Stereochemistry of Nitrogen Heterocycles. Part 64. Synthesis and Configuration of the Isomers of 2e-Methyl-5-ethynyl-trans-decahydroquinolin-5-ol. Correlation of the Structure with IR and PMR Spectra.

ChemInform Abstract

The stereochemistry of the ethynylation of 2e-methyl-trans-decahydroquinolin-5-one (I) is investigated. Ethynylation of (I) by acetylene (II) in the presence of KOH affords a mixture of the title compounds with axial (III) or equatorial (IV) orientation of the ethynyl group, the axial isomer (III) being the main component. The ethynylation of (I) with ethynylmagnesium bromide (V) or with alkali acetylides, e.g. (VI), in liquid ammonia again affords a mixture of the isomers (III) and (IV), the equatorial isomer (IV) now being the main component. Starting from the isomers (III) or (IV), the N-methyl derivatives (VIII) or (IX) and the acetyl derivatives (XI) and (XII) are prepared as well. Their structures are elucidated by ¹H NMR and by IR spectra.