NMR spectroscopic conformational analysis of 4‐methylene‐cyclohexyl pivalate—The effect of sp2 hybridization. (11th August 2017)

• Record Type: Journal Article
• Authors: Kleinpeter, Erich; Heydenreich, Matthias; Koch, Andreas; Krtitschka, Angela; Krüger, Tobias; Linker, Torsten
• Is Part Of: Magnetic resonance in chemistry. Volume 55:Number 12(2017:Dec.)
• Page Start: 1073
• Page End: 1078
• Publication Date: 2017-08-11
• Subjects: 4‐methylene‐cyclohexyl pivalate -- conformational analysis -- dynamic NMR spectroscopy -- exo‐methylene conformational effect at cyclohexane -- quantum chemical calculations; Nuclear magnetic resonance spectroscopy -- Periodicals; Chemistry, Organic -- Periodicals; Magnetic resonance -- Periodicals; 538.36
• DOI: 10.1002/mrc.4630
• Languages: English
• ISSNs: 0749-1581

Abstract

Abstract : The conformational equilibrium of the axial/equatorial conformers of 4‐methylene‐cyclohexyl pivalate is studied by dynamic NMR spectroscopy in a methylene chloride/freon mixture. At 153 K, the ring interconversion gets slow on the nuclear magnetic resonance timescale, the conformational equilibrium (−ΔG°) can be examined, and the barrier to ring interconversion (ΔG # ) can be determined. The structural influence of sp 2 hybridization on both ΔG° and ΔG # of the cyclohexyl moiety can be quantified. Abstract : The conformational equilibrium of the axial/equatorial conformers of 4‐methylene‐cyclohexyl pivalate is studied by dynamic nuclear magnetic resonance spectroscopy in a methylene chloride/freon mixture. At 153 K, the ring interconversion gets slow on the nuclear magnetic resonance timescale, the conformational equilibrium (−ΔG°) can be examined, and the barrier to ring interconversion (ΔG # ) can be determined. The structural influence of sp 2 hybridization on both ΔG° and ΔG # of the cyclohexyl moiety can be quantified.