2,5‐Anhydro‐ N ‐benzyl‐2‐ C ‐methyl‐ d ‐arabinonamide [(2 S ,3 R ,4 R )‐ N ‐benzyl‐3,4‐dihydroxy‐2‐methyltetrahydrofuran‐2‐carboxamide]

The size of the ring and relative configuration of the chiral centres in the title compound, C 13 H 17 NO 4 , formed by the preferential formation of the hindered five‐membered ring tetrahydrofuran rather than the expected three‐membered ring epoxide, was established by X‐ray crystallographic analysis; the absolute configuration was determined by the use of 2‐ C ‐methyl‐ d ‐ arabinono ‐lactone as the starting material. The crystal structure consists of hydrogen‐bonded layers lying with their hydrophobic surfaces in contact.