
%0 Journal Article
%A Katekar, GF 
%A Moritz, AG 
%T The hydroxyl stretching frequencies and conformations of Flavan-4-ols and Thiaflavan-4-ols
%J Australian Journal of Chemistry
%D 1969/11/01
%V 22
%N 11
%P 2337-2342
%K 
%R https://doi.org/10.1071/CH9692337
%U https://www.publish.csiro.au/paper/CH9692337 
%X The hydroxyl stretching frequencies of some 2,4-cis and 2,4-trans flavan-4-ols, thiaflavan-4-ols, and related compounds have been measured in dilute carbon tetrachloride solution. Characteristic frequencies are observed at 3626±2 cm-1 (free hydroxyl), 3616±1, and 3597±2 cm-1. The 3616 and 3597 cm-1 bands are assigned to pseudo-axial and pseudo-equatorial hydroxyl groups respectively. Evidence is presented to show that the frequency shifts arise from differences in the interaction of the hydroxyl group with the &#960;-electrons of the fused benzene ring, and that these flavans and thiaflavans exist in half- chair, rather than sofa conformations. 
