Synthesis of 4-Deoxy-4-C-hydroxymethyl-α-L-Lyxo-Pyranosyl Thymine
摘要:
The synthesis of 1-[4-deoxy-4-C-hydroxymethyl-alpha-L-lyxopyranosy]thymine has been accomplished by two synthetic routes both starting from methyl 2,3-O-isopropylidene-beta-D-ribopyranoside. The first route makes use of a ring opening, ring closure reaction sequence to increase the proportion of the desired L-isomers. The second route utilizes the soft nucleophilic character of malonyl anions and ozonolytic cleavage of enol ether to introduce the branched chain. The newly obtained pyranosyl nucleoside obtains a C-4(1) conformation with an equatorially oriented thymine moiety.