Morrill C, Jensen C, Just-Baringo X, Grogan G, Turner NJ, Procter DJ. Biocatalytic Conversion of Cyclic Ketones Bearing α-Quaternary Stereocenters into Lactones in an Enantioselective Radical Approach to Medium-Sized Carbocycles.
Angew Chem Int Ed Engl 2018;
57:3692-3696. [PMID:
29393988 PMCID:
PMC6055628 DOI:
10.1002/anie.201800121]
[Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Indexed: 01/11/2023]
Abstract
Cyclic ketones bearing α‐quaternary stereocenters underwent efficient kinetic resolution using cyclohexanone monooxygenase (CHMO) from Acinetobacter calcoaceticus. Lactones possessing tetrasubstituted stereocenters were obtained with high enantioselectivity (up to >99 % ee) and complete chemoselectivity. Preparative‐scale biotransformations were exploited in conjunction with a SmI2‐mediated cyclization process to access complex, enantiomerically enriched cycloheptan‐ and cycloctan‐1,4‐diols. In a parallel approach to structurally distinct products, enantiomerically enriched ketones from the resolution with an α‐quaternary stereocenter were used in a SmI2‐mediated cyclization process to give cyclobutanol products (up to >99 % ee).
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