The Rotatory Dispersion and Stereochemistry of Organic Compounds. XI. The Nitrates of Some Hexoses

Abstract

The rotatory dispersions (RD) and the ultraviolet absorptions of eight nitrates of galactopyranoside, altropyranosides, glucofuranoside, mannopyranosides and of glucopyranosides, and also of five hexosepyranosides, have been measured. Studies have also been made of the correlation between the configuration and the Cotton effect, the sign of which has been determined by the RD curve as well as by the dispersion constant computed from the dispersion data, and in some cases by means of the circular dichroism (CD). All the findings and conclusions are consistent with the generalized rule originally found with glucose derivatives (Y. Tsuzuki, K. Tanabe and K. Okamoto, This Bulletin, 39, 761 (1966)). The rule has been shown to be extensively applicable to several hexoses; namely, α-glycosides with a C–ONO₂ chromophore of a β(or D)-configuration show negative Cotton effects, and those with a C–ONO₂ group of a β(or L)-configuration exhibit positive Cotton effects, while with nitrates of β-glycosides the signs of the Cotton effects are exactly reversed (ref. Conclusion).