Synthesis, chemical transformations, and structure of 1,2,3,4-tetrahydrospiro(quinoline-2-cycloalkanes)

The cyclization of 1-(m-toluidino)-1-allylcyclohexane under acid-catalysis conditions gave 4,5- and 4,7-dimethyl-1,2,3,4-tetrahydrospiro(quinoline-2-cyclohexanes). The bromination, nitration, N-acylation, and N-allylation of 4-methyl-1,2,3,4-tetrahydrospiro[quinoline-2-cyclohexane(cyclopentane)] were studied. It was established that nitration takes place In the 6 and 7 positions, while bromination occurs in the 6 and 8 positions. The amino-Claisen rearrangement of N-allyltetrahydroquinolines is accompanied by quantitative allyl-vinyl isomerization. The stereochemistry of the synthesized spiro(tetrahydroquinolinecycloalkanes) was studied by PMR spectroscopy. © 1992 Plenum Publishing Corporation.