STEREOCHEMICAL STUDIES .31. RING-CLOSURE REACTION OF CIS AND TRANS-2-(BROMOMETHYL)CYCLOALKYLAMINES

Cyclization of the cis- and trans-2-(bromomethyl)cycloalkylamines (7)-(12) to the fused-ring azetidines (13)-(17) was investigated. The first-order rate constants for azetidine formation as a function of the ring size are in the order: cycloheptane > cyclopentane > cyclohexane for the cis-isomers; and cycloheptane > cyclohexane for the trans-isomers. Azetidine formation could not be induced from trans-2-(bromomethyl)cyclopentylamine (8). A plot of the E6 values for the reactions as a function of ΔS‡, shows an isokinetic correlation, with the exception of the point for trans-2-(bromomethyl)cyclohexylamine (10), where the main reaction is elimination.