A new protecting group and linker for uridine ureido nitrogen

(2,6-Dichloro-4-methoxyphenyl)(2,4,6-trichlorophenyl) methoxymethyl chloride [1, monomethoxydiph-enylmethoxylmethyl chloroide (MDPM-Cl)] shows a significant relative stability and 1 reacts with uridine ureido nitrogen in the presence of DBU to form the corresponding protected uridine 8 in 95% yield. The MDPM-protected uridines are stable to a wide variety of conditions utilized for the synthesis of analogs of capuramycin and muraymycins. Significantly, the MDPM protecting group can conveniently be deprotected by using 30% TFA in CH2Cl2. In addition, polymer-bound MDPM-Cl 23 is useful for immobilization of uridine derivatives.