Preparation of Cyclohexanones and Cyclopentanones of High Optical Purity

Article abstract of DOI:10.1021/jo01311a031

Cyclization of 3, prepared from 1-menthol, led to a 1:1 mixture of 4 and 5.These diastereomeric ketones, readily separated by chromatography, are versatile intermediates for the preparation of alkylated cyclohexanones.The absolute configuration of 5 was assigned by conversion to the known hydroxy ketal 9.This approach works equally well for the cyclopentane series.Thus, alkylated cyclohexanones and cyclopentanones of known absolute configuration will for the first time be routinely available.