Synthesis of substituted 5-N-(R)amino-4-cyclohexyl-1-ols by the reaction of secondary enaminones of β-dicarbonyl compounds with chalcones

Reaction of secondary enaminones of acetylacetone or acetoacetic ester with chalcones at room temperature, is shown to lead to 5- N -(R)amino-4-cyclohexen-1-ols, distinctly to the reaction of the related primary derivatives leading to 1,4-dihydropyridines. Tertiary enaminones of identical structure are found not reacting with chalcones under the similar conditions. The reasons for the difference in the behavior of primary, secondary and tertiary enaminones in the reaction with chalcones are discussed.