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1 H, 13 C, and 183 W NMR spectroscopic methods were used for the structural characterization of the tungstate and molybdate complexes of volemitol ( d - glycero - d - manno -hepitol) in aqueous solution. The major species (type E) are a pair of isomeric complexes formed at the arabino site in reversed orientation, i.e., HO-1,2,3,4 and HO-4,3,2,1. A single, minor complex is formed at the HO-3,4,5,6 altro site and is shown to be isostructural with the known single complexes of ribitol and d -altritol (type E′). The present NMR results support the hypothesis that complexes of type E′ are weaker than those of type E because they are destabilized by a steric strain due to the interaction of the side chain of the ligand with the site of chelation.

The molecular structures of the title heptitols were determined by X-ray crystallography, using direct methods, and refined to final residual parameters of R = 0.037 and 0.039, respectively. Each compound adopts a bent conformation. For α-sedoheptitol ( 1 ), this is not the expected conformation (with O-6 in the extended planar position). Instead, 1 adopts a conformation with a 1,3- parallel interaction between O-4 and C-7.

Because D-e~~t~l~O-D-g~~~C~O-OCtitOl is closely related to D-gijxero-D-mzmooctulose and both have been found in the avocado3, and because that octulose has been found also in Sedum3, a special search was made for the octitol in Sedum. To this end, 37.5 kg of S. speciabile Bor. was processed as described in the Experimental section, and &rally fractionated on a column of Dowex 5OW-X8 (Bat+) ion-exchange

An aqueous extract of 20 kg of the dried roots of Primula officinalis Jacq. has been deproteinized, deionized, fermented with bakers' yeast, and fractionated by chromatography on cellulose columns, Dowex 50W-X8 (Ba2+) resin columns, and sheets of filter paper. The following higher-carbon sugars were isolated: D-altro-heptulose (sedoheptulose), D-manno-heptulose, D-allo-heptulose, D-altro-3-heptulose, D-glycero-D-manno-heptose, D-glycero-D-gluco-heptose, D-glycero-D-manno-octulose, D-glycero-L-galacto-octulose, D-erythro-L-gluco-nonulose, and D-erythro-L-galacto-nonulose. Two higher-carbon polyhydric alcohols —volemitol (D-glycero-D-manno-heptitol) and β-sedoheptitol (D-glycero-D-gluco-heptitol)—were also isolated, as well as glycerol, erythritol, xylitol, myo-inositol, D-xylose, and primeverose. Of all these substances, only volemitol had previously been isolated from P. officinalis, although primeverose was known to occur there as a constituent of the glycosides primeverin and primulaverin. In addition, primeverose has been reduced to primeveritol (6-O-β-D-xylopyranosyl-D-glucitol), which was characterized further as the crystalline octaacetate; and the crystalline D-glycero-β-D-gluco-heptose has been converted into the new, crystalline D-glycero-β-D-gluco-heptose hexaacetate.