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Chuangxinmycin was shown by chemical correlation to have 3S,4R configuration asshown by 1.It is surprising that I has the opposite absolute configuration as indolmycin(7)withthe same carbon skeleton.The carboxyl group of norchuangxinmycin(14)and the methyl group of decarboxychuangxinmycin(18)were found to have preferred equatorial conformations with no observable anomeric effect in theformer.Thus the bulkier carboxyl group of chuangxinmycin itself must adopt the equatorial posi-tion predominantly,if not exclusively,in solution,a situation already found prevailing in the crys-talline state by X-ray diffraction.
Chuangxinmycin was shown by chemical correlation to have 3S, 4R configuration asshown by 1.It is surprising that I has the opposite absolute configuration as indolmycin (7) with the same carbon skeleton. Carboxyl group of norchuangxinmycin (14) and the methyl group of decarboxychuangxinmycin (18) were found to have the preferred equatorial conformations with no observable anomeric effect in theformer.Thus the bulkier carboxyl group of chuangxinmycin itself must adopt the equatorial posi-tion predominantly, if not exclusively, in solution, a situation already found in the crys -talline state by X-ray diffraction.