AbstractThe synthesis of four new monomers containing guanine or a guanine precursor was achieved. These were two isomeric acid ester derivatives of guanine and two isomeric vinyl ether derivatives of N2‐acetylguanine. In the case of the synthesis of the guanine acid esters IV and V, it was necessary to prepare first the guanine alcohol derivatives II and III. These N‐7 and N‐9 isomeric alcohols of guanine were separated by fractional crystallization. Subsequent esterification of these alcohols with maleic anhydride gave the desired products. In the other case, N2‐acetylguanine was alkylated with 2‐chloroethyl vinyl ether to yield the N‐7 and N‐9 isomer VI and VII, respectively. These were separated using flash column chromatography.