5-O-deaominyl 6-O-methyl erythronolide a derivatives, method for preparing same and application thereof for preparing biologically active products

The compounds of formula (I):

• ##STR15## in which:
• either R.sub.1 represents an alkyl radical containing up to 8 carbon atoms substituted by one or more alkyl radicals containing up to 8 carbon atoms, or by one or more aryl radicals containing up to 14 carbon atoms,
• or R.sub.1 represents an aryl radical containing up to 14 carbon atoms, optionally substituted by one or more alkyl, alkenyl or alkynyl radicals containing up to 8 carbon atoms, alkoxy or alkylthio radicals containing up to 8 carbon atoms, nitro, CF.sub.3 radicals or by one or more halogen atoms,
• or R.sub.1 represents a radical:
• ##STR16## in which Ra represents an alkyl or alkoxy radical containing up to 8 carbon atoms,
• Rb represents an alkyl radical containing up to 8 carbon atoms, optionally substituted by a heteroatom,
• Rc represents a hydrogen atom or an alkyl radical containing up to 8 carbon atoms,
• R.sub.2 and R.sub.3, identical or different, represent a trialkylsilyl radical in which the alkyl radical contains up to 8 carbon atoms, ##STR17## in which R'a, R'b, R'c and Rd represent an alkyl radical containing up to 8 carbon atoms, or an aralkyl radical containing up to 8 carbon atoms, optionally substituted by one or or more of the substituents indicated above for R.sub.1.