Biocatalytic Conversion of Cyclic Ketones Bearing α‐Quaternary Stereocenters into Lactones in an Enantioselective Radical Approach to Medium‐Sized Carbocycles |
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| Authors: | Charlotte Morrill Dr Chantel Jensen Dr Xavier Just‐Baringo Prof Gideon Grogan Prof Nicholas J Turner Prof David J Procter |
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| Institution: | 1. School of Chemistry, University of Manchester, Manchester, UK;2. Department of Chemistry, University of York, Heslington, York, UK |
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| 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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| Keywords: | biocatalysis cyclization lactones radicals samarium |
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