STRUCTURE OF A BIS(OSMATE ESTER) PRODUCED BY ADDITION OF OSMIUM-TETROXIDE TO DIETHYL 3,4-FURANDICARBOXYLATE

[mu-2,3-Bis(ethoxycarbonyl)tetrahydro-2,3,4,5-furantetrolato-O2,?? O3:O4,O5]-bis(dioxodipyridylosmium), [Os2(O)4(C10H12O9)(C5H5N)4], M(r) = 1037.06, monoclinic, C2/c, a = 18.593 (3), b = 13.240 (3), c = 16.639 (3) angstrom, beta = 122.10 (1)-degrees, V = 3469.8 (11) angstrom 3, Z = 4, D(m) 1.961, D(x) = 1.99 g cm-3, lambda-(Mo K-alpha) = 0.71073 angstrom, mu = 73.9 cm-1, F(000) = 1984, T = 298 K, R = 0.0384 for the 4235 data which were considered observed (F(o) greater-than-or-equal-to 3-sigma-F(o)) of the 5029 unique data collected. Addition of two OsO4/(pyridine)2 moieties to diethyl 3,4-furandicarboxylate yielded a bis(osmate ester), with Os atoms located trans to each other relative to the tetrahydrofuran ring. The tetrahydrofuran ring has the expected half-chair pucker.