MICROBIAL STEREO-DIFFERENTIATING REDUCTION IN [2.2]METACYCLOPHANE DERIVATIVES

Incubation of (±)-l-oxo[2.2]metacyclophane (9) with Rhodotorula rubra gave a mixture of (+)-axial alcohol 10 and (−)-equatorial alcohol 11 both with remarkably high optical purity. The same high stereoselectivity was observed when R. rubra was incubated with l, 10-dioxo[2.2]metacyclophane (12), which was converted into (−)-axial-equatorial diol 14 via (−)-axial ketol 13. R. rubra was also found to reduce (±)-[2.2]metacyclophane-4-aldehyde (20), affording a 13% yield of the (+)-4-hydroxymethyl derivative 21 with 11.7% optical purity. © 1979, American Chemical Society. All rights reserved.