14 and/or 15-hydroxy 6,9 hemiacetal erythromycin derivatives

A 6,9-hemiacetal-erythromycin compound or the salt thereof, in which said 6,9-hemiacetal-erythromycin compound is represented by the formula [1]:

• ##STR41## wherein R.sub.1 represents hydrogen or an aliphatic hydrocarbon group selected from the group consisting of a C.sub.1-6 alkyl, a C.sub.3-7 cycloalkyl, a C.sub.2-6 alkenyl and C.sub.2-6 alkynyl, and R.sub.2 represents hydrogen or an aliphatic hydrocarbon group as defined in R.sub.1 above, or R.sub.1 and R.sub.2 form a heterocyclic group having a carbon chain of 3 to 6 carbon atoms together with the adjacent nitrogen atom;
• R.sub.3 represents hydrogen or an acyl group selected from the group consisting of carboxylic acyl, sulfonic acyl, phosphorous acyl and phosphoric acyl;
• R.sub.4 represents a hydroxyl group and R.sub.5 represents a hydrogen or hydroxyl group;
• R.sub.6 represents hydrogen or a hydroxyl group;
• R.sub.7 represents hydrogen or a methyl group;
• R.sub.8 is selected from the group consisting of hydrogen, a hydroxyl group, an acyloxy group selected from the group consisting of carboxylic acyloxy, sulfonic acyloxy, phosphorous acyloxy and phosphoric acyloxy, and a C.sub.1-3 alkoxy group which is unsubstituted or substituted by C.sub.1-3 alkoxy or C.sub.2-6 alkoxyalkoy;
• and --A-- represents the formula [2]:
• ##STR42## wherein R.sub.9 and R.sub.10 both represent hydrogen or together form a double bond;
• and Z is selected from the group consisting of (i) the formula [3]:
• ##STR43## wherein R.sub.11 is selected from the group consisting of hydrogen, an acyl group selected from the group consisting of carboxylic acyl, sulfonic acyl, phosphorous acyl and phosphoric acyl, and a C.sub.1-3 alkyl group;
• and R.sub.12 is selected from the group consisting of hydrogen, a C.sub.1-6 carboxylacyl group, and a C.sub.1-3 alkyl group which is unsubstituted or substituted by a C.sub.1-3 alkylthio group, (ii) the formula [4]:
• ##STR44## wherein R.sub.13 is the same as defined in R.sub.11 above, (iii) the formula [5]:
• ##STR45## (iv) the formula [6]:
• ##STR46## and (v) the formula [7]:
• ##STR47## wherein Y is selected from the group consisting of (a) the formula >B--R.sub.14 ;
• wherein R.sub.14 represents a C.sub.1-6 alkyl group or an aryl group,
• (b) >S.dbd.O, >C.dbd.O, >C.dbd.S, and
• (c) the formula [8]:
• ##STR48## wherein R.sub.15 and R.sub.16, which may be the same or different, are selected from the group consisting of hydrogen and a C.sub.1-6 alkyl groups, or from a C.sub.1-6 cyclic alkyl group together with the adjacent carbon atom, or one of them is selected from the group consisting of hydrogen, a C.sub.1-6 alkyl group, and an aryl group, and the other represents a C.sub.1-3 dialkylamino group.