Preparation of chiral 3-oxocycloalkanecarbonitrile and its derivatives by crystallization-induced diastereomer transformation of ketals with chiral 1,2-diphenylethane-1,2-diol.

Chiral 3-oxocycloalkanecarbonitriles were prepared by fractional crystallization and crystallization-induced diastereomer transformation (CIDT) of diastereomeric ketals with (1,2)-1,2-diphenylethane-1,2-diol. Investigation of the crystal structures by X-ray diffraction analysis revealed that the difference in hydrogen bonds caused the discrepancy of the solubilities between () and () diastereomers. Furthermore, CIDT to afford the ()-diastereomer in good yield (95% yield) and with high diastereoselectivity (97% de) was accomplished, which is the first example of CIDT of neutral compounds formation of the diastereomeric ketal with (1,2)-1,2-diphenylethane-1,2-diol.