Isoprop­yl 2,5-anhydro-3,4-di-O-tert-butyl­diphenyl­sil­yl-L-ribonate

Determination of the crystal structure of the title compound, C₄₀H₅₀O₅Si₂, firmly established its relative configuration and hence that of some related tetra­hydro­furan carboxyl­ates. The material crystallizes with Z' = 2. Except for the chiral centres, the two independent mol­ecules are related by a pseudo-centre of symmetry.

(2R,3S,4S,5R)-Meth­yl 5-cyano-2,3:4,5-di-O-isopropyl­idene-2,3,4,5-tetra­hydroxy­penta­noate

The title nitrile, C₁₃H₁₉NO₆, a formal oxidation product, was unexpectedly isolated during hydrogenation of an azide precursor in the presence of palladium black.