Spacer conformation in biologically active molecules. Part 1. Structure and conformational preferences of 2-substituted benzoxazoles

Czylkowski R., Karolak-Wojciechowska J., Mrozek A., Yalcin I., Aki-Sener E.

JOURNAL OF MOLECULAR STRUCTURE, vol.598, no.2-3, pp.197-204, 2001 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 598 Issue: 2-3
  • Publication Date: 2001
  • Doi Number: 10.1016/s0022-2860(01)00630-5
  • Journal Name: JOURNAL OF MOLECULAR STRUCTURE
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.197-204
  • Keywords: crystal structure, HOMA, phenyl rings, X-ray structures, spacer conformation, benzoxazole moiety, 5-MEMBERED HETEROCYCLES, GEOMETRIC CONTRIBUTIONS, HOMA INDEX, AROMATICITY, DERIVATIVES, SEPARATION
  • Ankara University Affiliated: No

Abstract

The mutual position of two pharmacophoric elements in flexible biologically active molecules depends on the spacer conformation. This is true even for a two-atomic chain put to use as a spacer. It was established for 2-substituted-benzoxazoles containing two aromatic centres joined by -CH2-X- (X = S or O). From crystallographic studies of four molecules it was found that the role of heteroatom is essential for the whole molecule conformation. The spacer with X = S adopts the (-)synclinal conformation while for X = O the (+)antiperiplanar one. Such preferences were also found in the statistical data from Cambridge Structural Database (CSD). (C) 2001 Elsevier Science B.V. All rights reserved.