Asymmetric Synthesis of CDP840 by Jacobsen Epoxidation. An Unusual Syn Selective Reduction of an Epoxide
journal contributionposted on 26.12.1997, 00:00 by J. E. Lynch, W.-B. Choi, H. R. O. Churchill, R. P. Volante, R. A. Reamer, R. G. Ball
An asymmetric synthesis of the PDE IV inhibitor, CDP840 (3) is reported. The absolute stereochemistry was controlled by a Jacobsen epoxidation of the Z triaryl olefin 8 (89% ee) or the E triaryl olefin 9 (48% ee). The disparate results in stereocontrol were interpreted in terms of the “skewed side-on approach model” proposed by Jacobsen. LiBH4·BH3 reduction of the epoxides was found to proceed with retention of configuration.