N′-[(1S,3R,8R)-2,2-Dichloro-3,7,7,10-tetramethyltricyclo[6.4.0.01,3]dodecan-11-yl]acetohydrazide

Ahmed Benharref,Jean-Claude Daran,Moha Berraho,Mustapha Ait Elhad,Abdelouhed Oukhrib

doi:10.1107/s241431461600554x

Abstract

The title compound, C18H26Cl2N2O, was synthesized in four steps from β-himachalene (3,5,5,9-tetramethyl-2,4a,5,6,7,8-hexahydro-1H-benzocycloheptene), which was isolated from an essential oil of the Atlas cedar (Cedrus atlantica). It crystallizes with two independent molecules in the asymmetric unit. Each molecule is built up from fused six- and seven-membered rings and an appended three-membered ring. An acetylhydrazone substituent is attached to the six-membered ring. In both molecules the six-membered rings display half-chair conformations, whereas the seven-membered rings have boat conformations. In the two molecules, the mean planes of the two rings are inclined to one another by 59.9 (3) and 59.1 (3)°. In the crystal, the two molecules are linkedviaN—H...O hydrogen bonds, forming dimers with anR22(8) loop. Within the dimer there are also C—H...O hydrogen bonds present. The dimers are linkedviaC—H...Cl hydrogen bonds, forming slabs parallel to theabplane.

Highlights

The title compound, C18H26Cl2N2O, was synthesized in four steps from -himachalene (3,5,5,9-tetramethyl-2,4a,5,6,7,8-hexahydro-1H-benzocycloheptene), which was isolated from an essential oil of the Atlas cedar (Cedrus atlantica)
Structure description The bicyclic sesquiterpene -himachalene is the main constituent of the essential oil of the Atlas cedar (Cedrus atlantica) (El Haib et al, 2011)
In this paper we present the crystal structure of the title compound, N0-[(1S,3R,8R)-2,2dichloro-3,7,7,10-tetramethyltricyclo[6.4.0.01,3]dodecan-11-yl]acetohydrazide

Summary

DÁ Á ÁA

163 163 154 158 143 146 ethanol, several drops of concentrated HCl were added. The reaction mixture was heated at reflux for 5 h and evaporated under reduced pressure. The residue obtained was chromatographed on a silica gel column with a mixture of hexane and ethyl acetate as eluent (80/20). 1 g (2.7 mmol) of thiosemicarbazone was dissolved in 2 ml of pyridine and 2 ml of acetic anhydride. The mixture was heated at reflux during 1 h with magnetic stirring, and evaporated under reduced pressure. Chromatography of the residue on silica (hexane/ ethyl acetate, 90:10 v/v) allowed the isolation of the title compound with a yield of 90% (867 mg, 2.43 mmol). The product was recrystallized from ethyl acetate. C18H26Cl2N2O 357.33 Triclinic, P1 173 9.9172 (5), 10.0010 (5), 10.4124 (5) 86.863 (4), 84.173 (4), 66.037 (4) 938.73 (9) 2 Mo K 0.35 0.45 Â 0.2 Â 0.15

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