PROCESS FOR PREPARING ESTES OF 5-(4-O-(4-ACYL-2,6-DIDEOXY-3-C-METHYL-DELTA-L-RIBOHEXOPYRANOSYL)-3,6-DIDEOXY-3-DIMETHYL-AMINO-BETA-D-GLUCOPYRANOSYLOXYL)-3-ACYLOXY-12,13-EPOXY-6-FORMYL-METHYL-9-HYDROXY-4-METHOXY-8-METHYL-10-HEXADECEN-15-OLIDE AND5-(4-O-(4-ACYL-2,6-DIDEOXY-3-C-METHYL-DELTA-L-RIBOHEXOPYRA-NOSYL)-3,6-DIDEOXY-3-DIMETHYLAMINO-BETA-D-GLUCOPYRANOSYLOXY)-3-ACYLOXY-6-FORMYLMETHYL-9,13-DIHYDROXY-4-METHOXY-8-METHOXY-15-HEXADECANOLIDE