Novel macrolactone derivatives and process of producing them

Claim 1

A process of producing the aglycone of a macrolide compound of the formula (1) wherein A represents a carbonyl group or RO--< group; R represents a hydrogen atom, an acyl group, or a forosaminyl group; R 1 represents an aldehyde group protected by a cyclic acetal or a thioacetal; R 2 represents a hydrogen atom or an acyl group; R 3 represents a lower alkyl group; R 4 represents a hydrogen atom, a hydroxymethyl group, or mycinosyloxymethyl group; R 5 represents a methyl group or a methoxy group; R 6 represents a hydrogen atom or a methyl group; ˜ represents a single bond or a double bond; ---- represents a single bond, a double bond, or an oxiran-2,3-diyl group; and ------ means that the macrolactone ring forms a 16-membered ring or a 17-membered ring, which comprises reacting a macrolide compound of the formula (2) ##STR28## wherein B represents a hydrogen atom, a hydroxyl group, or an acylmycanosyloxy group ##STR29## R 7 represents an acyl group; and A; R 2 ; R 3 ; R 4 ; R 5 ; R 6 ; ˜ ; -----; and ------ have the same significance as in general formula (1) with a dihydric alcohol of up to 4 carbon atoms, a dithiol, of up to 4 carbon atoms or a mercapto-alcohol in the presence of an organic acid and then reacting the product with an oxidizing agent and an acylating agent, successively.