SYNTHESIS OF MEDIUM AND LARGE RINGS - 47 - SELECTIVE REACTIONS, RESOLUTION AND ABSOLUTE-CONFIGURATION OF BRIDGED HYDROAZULENES

Authors
TOCHTERMANN W PANITZSCH T PETROLL M HABECK T SCHLENGER A WOLFF C PETERS EM PETERS K VONSCHNERING HG
Citation
W. Tochtermann et al., SYNTHESIS OF MEDIUM AND LARGE RINGS - 47 - SELECTIVE REACTIONS, RESOLUTION AND ABSOLUTE-CONFIGURATION OF BRIDGED HYDROAZULENES, EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, (11), 1998, pp. 2651-2657
Citations number
23
Categorie Soggetti
Chemistry Inorganic & Nuclear
Journal title
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY → ACNP
ISSN journal
1434193X
Issue
11
Year of publication
1998
Pages
2651 - 2657
Database
ISI
SICI code
1434-193X(1998):11<2651:SOMALR>2.0.ZU;2-4
Abstract
Treatment of the bridged oxepine (+/-)-1 with a large excess of powder ed sodium methoxide in Et2O or with triphenylphosphonium methylide lea ds to the functionalized hydroazulenes (+/-)-2 (69%) and (+/-)-3 (81%) . Regioselective and stereoselective cyclopropanation of (+/-)-2 leads to the dibromocyclopropane derivative (+/-)-4. Epoxidation gives the epoxides (+/-)-5 and (+/-)-6. The resolution of the hydroazulenone (+/ -)-2 is achieved by fractional crystallization of the quinine salt (-) -8 of the corresponding mono acid (+/-)-7. The absolute configuration of (+)-7 is established by X-ray analysis of the quinine salt (-)-8.