1-(1-Carboxy­methyl-1,4-anhydro-2,3-O-isopropyl­idene-α-d-erythrofuranos­yl)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