Electron impact induced water elimination from hydroxyamides. 2—N‐acetyl‐ and N‐benzoyl‐4a‐hydroxydecahydroquinoline and N‐Methyl‐4a‐hydroxy‐2‐oxodecahydroquinoline

Abstract

Electron impact induced water elimination from the metastable molecular ions of N-acetyl-and N-benzoyl-4~-hydroxydecahydroquinoline mainly follows a formal [1,2] elimination. The initiating and ratedetermining step in the reaction is the hydrogen rearrangement from C-8a onto the carbonyl group. The transferred hydrogen is subsequently lost, together with the hydroxyl group. The h o s t complete absence of H,O loss from both diastereomers of N-methyl-4a-hydroxy-2-oxodecahydroquinohe confirms that the recation can only proceed when the carbonyl group is able to function as a 'hydrogen carrier' by occupying positions in the vicinity of both a hydrogen and the hydroxyl function.