SYNTHESIS OF MEDIUM AND LARGE RING-COMPOUNDS .43. SYNTHESIS AND ISOMERIZATION OF 8,9-DIMETHYL[6]PARACYCLOPHANE AND ITS BRIDGED DEWAR ISOMER

Authors
TOCHTERMANN W RODEFELD L DREESKAMP H SARGE SM
Citation
W. Tochtermann et al., SYNTHESIS OF MEDIUM AND LARGE RING-COMPOUNDS .43. SYNTHESIS AND ISOMERIZATION OF 8,9-DIMETHYL[6]PARACYCLOPHANE AND ITS BRIDGED DEWAR ISOMER, Liebigs Annalen, (12), 1996, pp. 1959-1961
Citations number
19
Categorie Soggetti
Chemistry
Journal title
Liebigs Annalen → ACNP
ISSN journal
09473440
Issue
12
Year of publication
1996
Pages
1959 - 1961
Database
ISI
SICI code
0947-3440(1996):12<1959:SOMALR>2.0.ZU;2-4
Abstract
An improved sonochemical procedure for the synthesis of dimethyl [6]pa racyclophane-8,9-dicarboxylate (2a) on a 10-g scale is described. The title compound 2d was synthesized from 2a in three steps. Irradiation of 2d yielded the Dewar isomer 3. In solution, the reaction enthalpy f or the thermal isomerization of 3 to 2d was determined to be -162 +/- 16 kJ . mol(-1), while the activation energy for this reaction was fou nd to be 123 +/- 12 kJ . mol(-1).