OMT ESTER DERIVATIVES

Ester derivatives of 5-O-mycaminosyl tylonolide (OMT) of the formula wherein R and R1 are selected from hydrogen, optionally substituted C1-C5-alkanoyl or optionally substituted benzoyl, phenylacetyl, or phenylpropionyl; R2 is hydrogen or an acyl group selected from: +TR p is 0 or 1; m and n are integers from 0 to 4; R3 is hydrogen, halo, C1-C4-alkyl, C3-C8-cycloalkyl, phenyl, C5-C8-cycloalkenyl, naphthyl, indenyl, tetralinyl, decalinyl, adamantyl, cinnoxacinyl, a monocyclic heterocyclic ring system comprising 3 to 8 atoms in the ring or a bicyclic heterocylic ring system comprising 6 to 11 atoms, provided that at least 1 atom of the ring system is carbon and at least 1 atom of the ring system is a heteroatom selected from O, N, and S; and wherein R3 and the connecting alkyl groups-(CH2)m- and -(CH2)n- are optionally substituted by one or two halo, methyl, ethyl, methoxy, amino, N-protected-amino, methylamino, dimethylamino, nitro, acetoxy, acetamido, azido, carbomethoxy, carboxamido, cyano, or hydroxyl groups, provided that, if the substituent is other than halo or alkyl, there can be no more than one substituent on any connecting -CH2- group; X is O, S, -NH-, -N(CH3)-, -C 3BOND C-, -CH=CH-, -C(CH3)=CH-, -CH=C(CH3)- or -C(CH3)=C (CH3)-; R4 and R5 are C1-C5-alkyl or optionally substituted phenyl or benzyl; provided that at least one of R, R1 and R2 must be other than hydrogen and that, when R1 is other than hydrogen, R must also be other than hydrogen; and salts thereof; which are useful antibiotics or intermediates to antibiotics, are provided.