Alistair James Stewart

2-Deoxy-l-ribose from an l-arabinono-1,5-lactone

Abstract A practical synthesis of 2-deoxy- l -ribose from l -arabinose depends on the efficient reduction by iodide of a triflate α to a lactone. The X-ray crystal structure of 3,4- O -isopropylidene- l - arabinono -1,5-lactone is reported.

(2R,3R,4R)-Meth­yl 2-bromo-3,4-dihydr­oxy-3,4-O-isopropyl­idenetetra­hydro­furan-2-carboxyl­ate

The relative configuration of the quaternary C atom in the title bromide, C9H13BrO5, prepared by bromination of the parent ester, has been determined by X-ray crystallographic analysis; the absolute configuration is known from the synthesis.

1-(1-Carboxy-methyl-1,4-anhydro-2,3-O-isopropyl-idene-α-d-erythrofuranos-yl)thymine.

X-Ray crystallography unequivocally determined the stereochemistry of the thymine base in the title compound, C14H18N2O7. The absolute stereochemistry was determined from the use of d-ribose as the starting material. There are two independent molecules in the asymmetric unit (Z′ = 2) which exist as N—H⋯O hydrogen-bonded pairs in the crystal structure.