Structures cristallines et moléculaires des muscs macrocycliques. I. La cis-civettone et les variétés polymorphes α et β de sa 2,4-dinitrophénylhydrazone

✍ Scribed by Gérald Bernardinelli; Raymond Gerdil

• Publisher: John Wiley and Sons
• Year: 1982
• Tongue: German
• Weight: 776 KB
• Volume: 65
• Category: Article
• ISSN: 0018-019X
• DOI: 10.1002/hlca.19820650215

✦ Synopsis

Crystal and Molecular Structure of Macrocyclic Musks. I. cis‐Civetone and polymorphous α‐ and β‐forms of his 2,4‐dinitrophenylhydrazone

cis‐Civetone (C~17~H~30~O) forms tetragonal plastic crystals, space groupe 14^1^; a = 9.95(4), c = 32.79(1) Å; Z = 8. The plastic phase exists in a wide temperature range and 731 reflexions could be collected at 153 K. The highly disordered structure model was obtained by the use of direct methods. The molecules appear as ring‐shaped diffuse electron‐density distributions located in special position.

Two polymorphous crystalline forms were isolated for the 2,4‐dinitrophenyl‐hydrazone of cis‐civetone (DNPHCC). Both forms are triclinic, space group P1. Z = 2 (α‐Form: a = 6.279(5), b = 12.605(8), c = 15.253(10) Å, α = 105.49(7). β = 100.31 (6), γ = 91.23(7)°; β‐Form: a = 7.950(2). b = 8.405 (2). c = 18.233(4) Å, α = 100.28(2), β = 92.29(3), γ = 94.18(2)°). The structures were solved by direct methods and refined to R = 0.11. Each polymorph is associated with a different quinquangular conformation of the macrocycle. In the crystals the intermolecular interactions between macrocycles and aromatic substituents are minimized, the DNPH group being oriented in a face‐to‐face arrangement across a centre of symmetry.

Empirical force field calculations show that the overall intluence of the DNPH moiety on the attached cycle does not significantly modify its conformation with regard to that of the ketone itself.