Clarithromycin Monohydrate: A Synchrotron X-Ray Powder Study

In the crystal structure of the title compound, clarithromycin (CAM) monohydrate, C(38)H(69)NO(13)·H(2)O, the water mol-ecule behaves as a proton donor and is hydrogen bonded to the hy-droxy O atom of the CAM cladinose ring. The hy-droxy O atom also behaves as a proton donor, forming an inter-molecular hydrogen bond with one of the hy-droxy groups of the 14-membered aglycone ring. The CAM mol-ecules are linked through these hydrogen bonds into chains running parallel to the c axis.