Universal NMR Databases for Contiguous Polyols

On the basis of 1,2,3-triols la∼d, 1,2,3,4-tetraols 2a∼h, and 1,2,3,4,5-pentaols 3a∼p, NMR databases with four types of profile-descriptors (¹³C-, ¹H-, and ¹H(OH)-chemical shifts and vicinal spincoupling constants) for contiguous polyols are reported. To systematically assess the relative values of these databases, a case study has been conducted on heptaols 4a∼d, through which the γ- and δ- effects have been recognized to refine the ¹³C and ¹H chemical shift profile predicted via an application of the concept of self-contained nature. The magnitudes of γ- and δ- effects depend on a specific stereochemical arrangement of the functional groups present in both the inside and outside of a self-contained box and are significant only for the stereoisomers belonging to a specific sub-group. With the exception of the stereochemical arrangement of functional groups belonging to a specific sub-group, the γ- and δ- effects can, at the first order of approximation, be ignored for the stereochemical analysis of unknown compounds. For the stereoisomers belonging to a specific sub-group, it is necessary to refine, with incorporation of the γ- and δ- effects, the profile predicted at the first order of approximation. With use of heptaols 4a∼d, the values of ³J_H, _H profiles have been assessed. Two methods, one using profiles consisting of three contiguous ³J_H,_H constants and the other using profiles consisting of two contiguous ³J _H,_H constants, have been developed. A stereochemical analysis based on three, or two, contiguous ³J_H, _H profiles is operationally simplerthan one based on ¹³C and ¹H chemical shift profiles. Therefore, it is recommended to use a ³J_H,_H profile as the primary device to predict the stereochemistry of unknown polyols and ¹³C and ¹H chemical shift profiles as the secondary devices to confirm the predicted stereochemistry.