A fused GalNAc-thiazole from a singular and unanticipated fragmentation

Attempted O-desilylation of an elaborated GalNAc-thiazoline t-butyl ester gave rise instead to a GalNAc-thiazole wherein the two-carbon acetate side chain has been severed by a process heretofore undescribed. The corresponding ether ester rearranged to a C-furanoside by a quite different pathway.