“…2) has been synthesized independently in three laboratories (231)(232)(233)), but appears to be devoid of significant biological activity (233). The following interesting compounds have been synthesized, but no biological information on them is yet available : 2',3'-unsaturated derivatives of uracil and thymine (234), 3'-aminohexapyranosyl uracil (235), arabinohexapy ranosyl and deoxyribohexapyranosyl uracils (236), uridine and arabinosyl uridine 5'-carboxylic acids and uridine-5-carboxaldehyde and various hydrazone derivatives (237), 2'-O-methyl uridine and cytidine (238), and (X-and {j-anomers of arabinosyl and lyxosyl uracil and thymine (239).…”