Compounds of the formula ##STR1## wherein R is selected from the group consisting of hydrogen and groups easily removable by acid hydrolysis or hydrogenolysis, R' is selected from the group consisting of hydrogen, alkyl of 1 to 4 carbon atoms, alkenyl and alkynyl of 2 to 4 carbon atoms and groups easily removable by acid hydrolysis or hydrogenolysis, A is selected from the group consisting of hydrogen, alkali metal and equivalents of an alkaline earth metal or magnesium and an organic amine base with the proviso that when R' is a group easily removable by acid hydrolysis or hydrogenolysis, R is also and when R' is hydrogen, R also is hydrogen and the wavy line means the OR' group may be in either one of the two possible syn or anti positions having antibiotic activity and process for their preparation.
化合物的公式为##STR1##其中R是从氢和易于通过酸
水解或氢解去除的基团中选择的,R'是从1到4个碳原子的烷基,2到4个碳原子的烯基和炔基以及易于通过酸
水解或氢解去除的基团中选择的,A是从氢,碱
金属和等价的碱土
金属或
镁以及有机胺基中选择的,但是当R'是易于通过酸
水解或氢解去除的基团时,R也是如此,当R'是氢时,R也是氢,波浪线表示OR'基团可以位于两个可能的同步或反向位置中具有抗生素活性及其制备方法。