| 摘要 |
In a process for photo-oxygenation of an anhydrotetracycline compound to the corresponding 6-deoxy-6-hydroperoxy dehydrotetracycline compound in a reaction-inert solvent by introduction of molecular oxygen during irradiation with light of wavelength between 300 and 450mm , the oxygenation is conducted in the presence of at least 0.0005 gms per 100 ml. of a dissolved additive in the solvent, the additive being 1,2- or 3, 4-benzpyrene, cholanthrene, 18-, 19- or 20-monomethylcholanthrene, 1, 2, 5, 6-dibenzanthracene or a phenanthrene of the formula <FORM:0976827/C1/1> wherein one or two adjacent pairs of the R1, R2, R3 and R4 substituents completes a benzor monomethylbenz-fused ring and, where only one R substituent pair completes a fused ring, one of the two remaining R substituents is methyl and the other is hydrogen or methyl. The 6-deoxy-6-hydroperoxy dehydrotetracycline compounds may be reduced to give the corresponding dehydrotetracycline and tetracycline compounds. The Specification contains many examples describing the photo-oxygenation of many anhydrotetracycline compounds with the use of a wide range of additives. Specifications 785,047 and 800,699 are referred to. |
