By acetylation of 8-carbamoyloxymethyl-5-formyl-7,9-dihydroxy-3,9-epoxy-1,1a,2,8,9,9a-octahydroazirino[2,3-c][1]benzazocine (FR-900482) (I) with acetic anhydride - pyridine.
FR-900482 (I) was produced by culturing Streptomyces sandaensis No. 6897 (FERM P-7654) and recovered by conventional methods. The acetylation of (I) with acetic anhydride gave the triacetyl derivative (II), which was selectively deacetylated with NaHCO3 in cool methanol yielding the diacetate (III). Finally, this compound was methylated by means of methyl iodide and K2CO3 in warm acetone.