Synthesis and Stereochemical Assignment of Crypto-Optically Active 2H6-Neopentane

Citation:

Masarwa, A. ; Gerbig, D. ; Oskar, L. ; Loewenstein, A. ; Reisenauer, H. P. ; Lesot*, P. ; Schreiner*, P. R. ; Marek*, I. Synthesis and Stereochemical Assignment of Crypto-Optically Active 2H6-Neopentane. Angew. Chem. Int. Ed. 2015, 54, 13106–13109.
Synthesis and Stereochemical Assignment of Crypto-Optically Active 2H6-Neopentane

Abstract:

The determination of the absolute configuration of chiral molecules is at the heart of asymmetric synthesis. Here we probe the spectroscopic limits for chiral discrimination with NMR spectroscopy in chiral aligned media and with vibrational circular dichroism spectroscopy of the sixfold-deuterated chiral neopentane. The study of this compound presents formidable challenges since its stereogenicity is only due to small mass differences. For this purpose, we selectively prepared both enantiomers of 2H6-1 through a concise synthesis utilizing multifunctional intermediates. While NMR spectroscopy in chiral aligned media could be used to characterize the precursors to 2H6-1, the final assignment could only be accomplished with VCD spectroscopy, despite the fleetingly small dichroic properties of 1. Both enantiomers were assigned by matching the VCD spectra with those computed with density functional theory.

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Last updated on 05/08/2016