Original scientific paper

Crystal and Molecular Structure of 9-deoxo-9a-ethyl-9a-aza-9a-homoerythronolide A

Boris Kamenar ; Laboratory of General and Inorganic Chemistry, Faculty of Science, University of Zagreb, PO Box 153, 41001 Zagreb, Croatia, Yugoslavia
Draginja Mrvoš-Sermek ; Laboratory of General and Inorganic Chemistry, Faculty of Science, University of Zagreb, PO Box 153, 41001 Zagreb, Croatia, Yugoslavia
Zrinka Banić ; Laboratory of General and Inorganic Chemistry, Faculty of Science, University of Zagreb, PO Box 153, 41001 Zagreb, Croatia, Yugoslavia
Ante Nagl ; Institute of Textile and Clothing, Faculty of Technology, University of Zagreb, Croatia, Yugoslavia
Gabrijela Kobrehel ; PLIVA, Pharmaceutical, Chemical, Food and Cosmetic Industry, Research Institute, 41001 Zagreb, I. L. Ribara 87, Croatia, Yugoslavia

Abstract

The title compound is the 15-membered aglycone ring of the N-ethyl derivative of the new semisynthetic macrolide antibiotic 9-deoxo-9a-aza-9a- homoerythromycin A. Its molecular and crystal structure has been determined from the diffractometer X-ray intesity data and refined by the least-squares method to the reliability index R= 0.064. The crystals are orthorhombic, space group P2i2i2i, with cell parameters a = 17.784 (5), b = 22.009 (5), c = 13.675 (3) A. Although the molecular structure is similar to the analogous N-methyl derivative, as well as to other compounds with such 15-membered aglycone rings, the packing of molecules in the crystal structure is significantly different In the present structure, all hydroxyl-hydrogen atoms of the aglycones take part in the hydrogen bondings between neighbouring molecules forming helices around each screw diad axis. The helices are interconnected by an additional hydrogen bond.

Keywords

Hrčak ID:

137305

URI

https://hrcak.srce.hr/137305

Publication date:

15.10.1991.

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