https://www.selleckchem.com/pr....oducts/auranofin.htm
The microwave spectrum of the fruit ester methyl valerate was recorded using two molecular jet Fourier transform spectrometers covering the frequency range from 2 to 40 GHz. Quantum chemical calculations yielded 11 minima for the anti ester configuration, among them two were identified in the experimental spectrum. The methyl group in the methoxy moiety undergoes internal rotation, leading to torsional splittings of all rotational transitions into doublets. The barrier to internal rotation of the methoxy methyl group was deduced to be