15-hydroxy 6,9-hemiacetal erythromycin compounds

A process for preparing the 6,9-hemiacetal-erythromycin compound represented by the formula (16):

• ##STR58## wherein R.sub.3 represents hydrogen or a substituted or unsubstituted aliphatic hydrocarbon group and R.sub.2 represents hydrogen or a substituted or unsubstituted aliphatic hydrocarbon group, or R.sub.1 and R.sub.2 form a heterocyclic group together with the adjacent nitrogen atom;
• R.sub.3 represents hydrogen or a substituted or unsubstituted acyl group;
• R.sub.6 represents hydrogen or a hydroxyl group;
• R.sub.8 represents hydrogen, a hydroxyl group, a substituted or unsubstituted acyloxy group or a substituted or unsubstituted alkoxy group;
• and --A-- represents the formula (2):
• ##STR59## wherein R.sub.9 and R.sub.10 both represent hydrogen or both form a chemical bond;
• and Z represents the formula (3):
• ##STR60## wherein R.sub.11 represents hydrogen, a substituted or unsubstituted acyl group or a substituted or unsubstituted alkyl group;
• and R.sub.12 represents hydrogen, a lower carboxylacyl group or an alkyl group which may have alkylthio as a substituent, or Z represents the formula (4):
• ##STR61## wherein R.sub.13 represents hydrogen, a substituted or unsubstituted acyl group or a substituted or unsubstituted alkyl group, or Z represents the formula (5):
• ##STR62## or Z represents the formula (6):
• ##STR63## or Z represents the formula (7):
• ##STR64## wherein Y represents the formula >B--R.sub.14 ;
• wherein R.sub.14 represents an alkyl group or an aryl group;
• >S.dbd.O, >C.dbd.O, >C.dbd.S or the formula (8):
• ##STR65## wherein R.sub.15 and R.sub.16, which may be the same or different, represent hydrogen or alkyl groups or form a cyclic alkyl group together with the adjacent carbon atom, or one of them represents hydrogen, an alkyl group or an aryl group, and the other represents a dialkylamino group, or --A-- represents the formula (9):
• ##STR66## wherein Z' represents the formula (10):
• ##STR67## wherein R.sub.17 represents hydrogen, a substituted or unsubstituted acyl group or a substituted or unsubstituted alkyl group, or the salt thereof,
• which comprises reacting a 6,9-hemiacetal-erythromycin compound represented by the formula (17):
• ##STR68## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.6, R.sub.8 and --A-- have the same meanings as defined above,
• or a salt thereof with an oxidase derived from an actinomycete or a liver of a mammal.