| 摘要 |
3" ,4"-Acyltylosin or 3, 3" ,4"-acyltylosin(I; R1 = H, acetyl, lower alkanoyl; A1, A2 = acetyl, propionyl, butyryl, iso valeryl), useful as antibiotic, were prepd. from tylosin Thus, 10 g tylosin stirred with 20 ml Ac2O and 7 g K2CO3 at 60≦̸C for 24 hr, poured into H2O, and extd. with CHCO3 at pH 9.5 gave 10.2 g crude 18,2', 4",4"'-teradcetyl-3,-0-cyclotylosin, which was heated with 4 ml isovaleric anhydride in C5H5N at 100≦̸C for 110 hr to give 2.8 g 18,2',3",4"-tetraacetyl-3,18-0-cyclo-4"-isovaleryltylosin.
|
