Crystal and molecular structures of d-glycero-d-manno-heptitol (α-sedoheptitol, volemitol) and d-glycero-d-gluco-heptitol (β-sedoheptitol)

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.