The fungus Mortierella isabellina NRRL 1757 catalyzes the reduction of 2-oxocyclopentanecarboxamides with very high enantioselectivity giving; in most cases, the corresponding enantiopure 2-hydroxycyclopentanecarboxamides. The presence or absence of a substituent on the amidic nitrogen has a strong influence on the diastereoselectivity achieved in these processes. Optically active hydroxyamides prepared in these microbial reductions are used as starting materials for the preparation of optically active 2-aminomethyl- and 2-aminocyclopentanols.
Quirós, M., Rebolledo, F., & Gotor, V. (1999). Bioreduction of 2-oxocyclopentanecarboxamides: Syntheses of optically active 2-aminomethyl- and 2-aminocyclopentanols. Tetrahedron Asymmetry, 10(3), 473–486. https://doi.org/10.1016/S0957-4166(99)00016-6