C-stannylated carbohydrate derivatives, part 5. 1,2:5,6-Di-O-isopropylidene-3-C-(organostannyl)- and -3-C-(phenylstannyl)methyl-α-D-allofuranose compounds. X-Ray crystal and molecular structure of 1,2:5,6-di-O-isopropylidene-3-C-(triphenylstannylmethyl)-α-D-allofuranose

The crystal structure and the solid state (13C and 119Sn) and solution (1H, 13C and 119Sn) NMR spectra of 1,2:5,6-di-O-isopropylidene-3-C-triphenylstannylmethyl-α-D-allofuranose (1; R = Ph) have been obtained. The structure of compound (1; R = Ph) is similar in both phases and contains a slightly distorted tetrahedral tin atom [C–Sn–C valency angles range from 103.8(3) to 114.9(5)°]. The poxygen atom at C(3) in compound (1; R = Ph) is 3.01(1)A distant from Sn and is ideally sited to take part in nucleophilic assistance during Ph–Sn bond-cleavage reactions. Reactions of compound (1; R = Ph) and 1,2:5,6-di-O-isopropyl idene-3-C-R3Sn-α-D-allofuranose with electrophiles (e.g., I2or CF3CO2H) are also reported.