Substituent effects on the reduction of 2–alkylcyclohexanones by LiAlH4: an investigation of conformational equilibria and transition states |
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| Authors: | Cleverson C. Bocca Roberto Rittner Alan P. da Silva Ernani A. Basso |
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| Affiliation: | 1. Chemistry Institute, State University of Campinas, Campinas, SP, Brazil;2. Chemistry Department, University of Maringa, Maringá, PR, Brazil |
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| Abstract: | Transition state (TS) structures for the reduction of 2‐Me and 2‐i‐Pr‐cyclohexanone by LiAlH4 were optimized by density functional theory (B3LYP/6‐31G(d,p)). Four TS structures corresponding to axial and equatorial attacks by LiAlH4 were located for each ketone conformer. Electronic potential maps were used to investigate the substituent electronic effect on the TS stabilization. The uneven carbonyl orbital distribution in the LUMO (π*) was also analyzed. Reduction stereoselectivity was shown to depend on both the ketone conformational ratio and on the reaction TS. Copyright © 2010 John Wiley & Sons, Ltd. |
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| Keywords: | cyclohexanones electrostatic potential map reduction by LiAlH4 stereoselectivity theoretical calculations |
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