Structure of C-2801X, a new cephamycin-type antibiotic.

The C-3 side chain moiety of C-2801X, a new cephamycin-type antibiotic, was almost quantitatively obtained by Dowex 50-catalyzed hydrolysis, and its structure was established as 3,4-dihydroxy-α-methoxycinnamic acid (I) by spectroscopic analyses and synthesis. The full structure of C-2801X was also assumed to be XIII by NMR analysis.