An unexpected rearrangement of pent-4-enofuranosides to cyclopentanones upon hydrogenolysis of the anomeric benzyl group.

During our synthesis toward the unique nucleoside antibiotic A201A, we were surprised to find that a benzyl arabino-pent-4-enofuranoside underwent a Ferrier II-like rearrangement readily to provide the corresponding cyclopentanone derivative in high yield and stereoselectivity upon hydrogenolysis of the anomeric benzyl group.