Abstract: A compound selected from the group consisting of a compound of the formula ##STR1## wherein R is selected from the group consisting of hydrogen, alkyl, alkylthio and haloalkyl of 1 to 6 carbon atoms, alkenyl and alkynyl of 2 to 6 carbon atoms, optionally substituted arylthio of 6 to 10 carbon atoms, aryl of 6 to 12 carbon atoms, acyl of an organic carboxylic acid of 1 to 12 carbon atoms, --CN, cycloalkyl of 3 to 6 carbon atoms and --(CH.sub.2).sub.m --Re, m is an integer from 1 to 3, Re is --OH or --SH or --Salk, Alk is alkyl of 1 to 6 carbon atoms, X is selected from the group consisting of oxygen, N--O--R.sub.1, ##STR2## or =X is H.sub.2 or ##STR3## R.sub.A and R.sub.B are individually selected from the group consisting of hydrogen, halogen and alkyl of 1 to 6 carbon atoms, R.sub.1 is hydrogen or alkyl of 1 to 6 carbon, R' is hydrogen or acyl, the wavy lines indicate --or -position, Y is selected from the group consisting of oxygen, NOR, ##STR4## or =Y is ##STR5## H.sub.