A series of substituted 1, 2, 3, 6-(5) and 1, 2, 5, 6-tetrahydro-pyridines (6) have been synthesised via intramolecular 1, 6-Michael addition of methoxycarbonyl-2, 4-dienylamines (10). The kinetics of these reactions have been investigated and an explanation of substituent effects is advanced. Also a new route to m-hydroxybenzoic acids has been established by cyclisation of substituted hexa-3, 4: 5, 6-dienoic acids.
