The stereochemical course of formic acid reduction of enamines

Abstract Formic acid reduction of enamines derived from 2-methyl- and 2-(β-cyanoethyl)-cyclohexanone has been shown to proceed with high stereoselectivity, the cis to trans ratio of the resulting cyclohexylamines being about 9. The stereochemistry of the isomers has been established by Cope-eliminations of the corresponding N-oxides and by applying the boiling point and refractive index relations of the Auwers-Skita rules.