O-[(Triorganostannyl)methyl] derivatives of 1,2-O-isopropylidene-α-D-xylofuranose

Hydroxy group interactions in stannylated carbohydrates. Structures and thermal stabilities of 5-deoxy-5-C-(Ph3Sn)-1,2-O-isopropylidene-α-D-xylofuranose, 5-deoxy-5-C-(IPh2Sn)-1,2-O-isopropylidene-α-D- and -L-xylofuranose, and 5-deoxy-5-C-(I2PhSn)-1,2-O-isopropylidene-α-D- and -L-xylofuranose

“…However, in each molecule there is also a Sn ring-oxygen (O4) separation of 3.262(8) and 3.2520 (14) Å in ()-3 and ()-3, respectively, well within the sum of the van der Waals radii of 3.70 Å. 35 If these are considered as weak bonds, then the tin coordination number is increased to 5, with the O4 and C9 atoms in the quasi axial sites and thus the carbohydrate species acts here as a ligand creating a four membered chelate ring. The weakness of the Sn-O4 interactions is also clearly indicated from the trans axial O4-Sn-C9 and the axial-Sn-equatorial, O4-Sn-C5 angles [155.…”

“…f Molecule 2. g Molecule 1. h Ref. 34. i ()-14: 1,2-O-isopropylidene-5-O-triphenylmethyl-3-O-(triphenylstannylmethyl)-α--xylofuranose 35. …”