Reaction SMILES: [CH3:1][C@H:2]1[CH2:33][C:32]([CH3:34])=[CH:31][C@@H:30]([CH2:35][CH:36]=[CH2:37])[C:28](=[O:29])[CH2:27][C@H:26]([OH:38])[C@@H:25]([CH3:39])[C@@H:24](/[C:40](/[CH3:51])=[CH:41]/[C@H:42]2[CH2:47][C@@H:46]([O:48][CH3:49])[C@H:45]([OH:50])[CH2:44][CH2:43]2)[O:23][C:21](=[O:22])[C@H:20]2[N:15]([CH2:16][CH2:17][CH2:18][CH2:19]2)[C:13](=[O:14])[C:11](=[O:12])[C@:9]2([OH:52])[O:10][C@@H:5]([C@@H:6]([O:54][CH3:55])[CH2:7][C@H:8]2[CH3:53])[C@@H:4]([O:56][CH3:57])[CH2:3]1.C(OC(=O)C)(=O)C.[CH3:65][S:66]([CH3:68])=O>C(OCC)(=O)C>[CH2:35]([CH:30]1[CH:31]=[C:32]([CH3:34])[CH2:33][CH:2]([CH3:1])[CH2:3][CH:4]([O:56][CH3:57])[CH:5]2[O:10][C:9]([OH:52])([CH:8]([CH3:53])[CH2:7][CH:6]2[O:54][CH3:55])[C:11](=[O:12])[C:13](=[O:14])[N:15]2[CH:20]([CH2:19][CH2:18][CH2:17][CH2:16]2)[C:21](=[O:22])[O:23][CH:24]([C:40]([CH3:51])=[CH:41][CH:42]2[CH2:43][CH2:44][CH:45]([OH:50])[CH:46]([O:48][CH3:49])[CH2:47]2)[CH:25]([CH3:39])[CH:26]=[CH:27][C:28]1=[O:29])[CH:36]=[CH2:37].[CH2:35]([CH:30]1[CH:31]=[C:32]([CH3:34])[CH2:33][CH:2]([CH3:1])[CH2:3][CH:4]([O:56][CH3:57])[CH:5]2[O:10][C:9]([OH:52])([CH:8]([CH3:53])[CH2:7][CH:6]2[O:54][CH3:55])[C:11](=[O:12])[C:13](=[O:14])[N:15]2[CH:20]([CH2:19][CH2:18][CH2:17][CH2:16]2)[C:21](=[O:22])[O:23][CH:24]([C:40]([CH3:51])=[CH:41][CH:42]2[CH2:43][CH2:44][CH:45]([O:50][CH2:65][S:66][CH3:68])[CH:46]([O:48][CH3:49])[CH2:47]2)[CH:25]([CH3:39])[CH:26]([OH:38])[CH2:27][C:28]1=[O:29])[CH:36]=[CH2:37]
Reactant: CS(C)=O
Reactant: C=CC[C@@H]1C=C(C)C[C@H](C)C[C@H](OC)[C@H]2O[C@@](O)(C(=O)C(=O)N3CCCC[C@H]3C(=O)O[C@H](/C(C)=C/[C@@H]3CC[C@@H](O)[C@H](OC)C3)[C@H](C)[C@@H](O)CC1=O)[C@H](C)C[C@@H]2OC
Agent: C=CC[C@@H]1/C=C(\C)C[C@H](C)C[C@H](OC)[C@H]2O[C@@](O)(C(=O)C(=O)N3CCCC[C@H]3C(=O)O[C@H](/C(C)=C/[C@@H]3CC[C@@H](O)[C@H](OC)C3)[C@H](C)[C@@H](O)CC1=O)[C@H](C)C[C@@H]2OC
Solvent: CC(=O)OC(C)=O
Solvent: CCOC(C)=O
Product: C=CCC1C=C(C)CC(C)CC(OC)C2OC(O)(C(=O)C(=O)N3CCCCC3C(=O)OC(C(C)=CC3CCC(O)C(OC)C3)C(C)C=CC1=O)C(C)CC2OC
Product: C=CCC1C=C(C)CC(C)CC(OC)C2OC(O)(C(=O)C(=O)N3CCCCC3C(=O)OC(C(C)=CC3CCC(OCSC)C(OC)C3)C(C)C(O)CC1=O)C(C)CC2OC
Temperature: 25 °C
Reaction time: 14 h

Procedure:
To a solution of the FR-900506 substance (100 mg) in dimethyl sulfoxide (1.5 ml) was added acetic anhydride (1.5 ml), and the mixture was stirred at room temperature for 14 hours. The reaction mixture was diluted with ethyl acetate and washed with a saturated aqueous sodium hydrogen carbonate, water and an aqueous sodium chloride. The organic layer was dried over sodium sulfate, filtered and then concentrated under reduced pressure. The residue was subjected to thin layer chromatography on silica gel (developing solvent: diethyl ether) to give 17-allyl-1,14-dihydroxy-23,25-dimethoxy-13,19,21,27-tetramethyl-12-[2-(4-methylthiomethoxy-3-methoxycyclohexyl)-1-methylvinyl]-11,28-dioxa-4-azatricyclo[22.3.1.04,9 ]octacosa-14,18-diene-2,3,40,16-tetraone (51 mg), 17-allyl-1-hydroxy-12-[2-(4-hydroxy-3-methoxycyclohexyl)-1-methylvinyl]-23,25-dimethoxy-13,19,21,27-tetramethyl-11,28-dioxa-4-azatricyclo[22.3.1.04,9 ]octacosa-14,18-diene-2,3,10,16-tetraone (18 mg) and 17-allyl-1,14-dihydroxy-23,25-dimethoxy-13,19,21,27-tetramethyl-12-[2-(4-methylthiomethoxy-3-methoxycyclohexyl)-1-methylvinyl]-11,28-dioxa-4-azatricyclo[ 22.3.1.04,9 ]octacos-18-ene-2,3,10,16-tetraone 10 mg), respectively.