| abstract |
NEW MATERIAL:A compound of formula I (R 1 is carboxy, tetrazolyl, carbamoyl; R 2 , R 3 are H, OH-protecting group; R 4 is H, 1W4C alkyl; R 5 is alkyl, alkenyl; S is ethylene, vinylene, -O-, -CH 2 -; m is 0W5; n is 2W5). n EXAMPLE: 5-Oxo-16-phenoxy-17,18,19,20-tetranolprostagladin E 1 methyl ester. n USE: Antiulcerative. It shows anti-ethanol ulcerative action with reduced side-effect of blood platelet coagulation. n PREPARATION: An aldehyde derivative of formula II (R 2 , R 3 , R 7 is hydroxyl- protecting group) is used as a starting substance and subjected to the Witting reaction, reduction, deprotection to give a compound of formula III (R 1 is carboxy, tetrazolyl). The compound of formula III is oxidized with an oxidizing agent such as chromic acid anhydride-pyridine complex in a solvent such as methylene chloride at -70°C W room temperature to give the compound of formula I. n COPYRIGHT: (C)1988,JPO&Japio |