Generation and trapping of a highly strained bicyclic alkyne: Tricyclo[6.3.1.0(2,7)]dodeca-2,4,6-trien-9-yne

TÜMER F., Taskesenligil Y., BALCI M.

JOURNAL OF ORGANIC CHEMISTRY, cilt.66, sa.11, ss.3806-3810, 2001 (SCI-Expanded) identifier identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 66 Sayı: 11
  • Basım Tarihi: 2001
  • Doi Numarası: 10.1021/jo0017537
  • Dergi Adı: JOURNAL OF ORGANIC CHEMISTRY
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.3806-3810
  • Atatürk Üniversitesi Adresli: Evet

Özet

High-temperature bromination of 10-bromotricyclo[6.3.1.0(2,7)]dodeca-2,4,6,9-tetraene (8) resulted mainly in the formation of two isomeric tribromides (16 and 17) whose dehydrobromination with DBU afforded the corresponding 9,10-dibromotricyclo [6.3.1.0(2,7)] dodeca-2,4,6,9-tetraene (14). Treatment of 14 with tert-butyllithium in THF at -78 degreesC produces the strained bicyclic alkyne (10) which is trapped by 1,3-diphenylisobenzofuran to give two isomeric cycloadducts 12a and 12b. The adducts 12a and 12b were found to readily rearrange to the isomeric ketones 19a and 19b upon chromatography. Upon treatment with potassium tert-butoxide, the adducts 12a and 12b undergo base-catalyzed double bond isomerization to give four products 20-23. Furthermore, reaction of 14 with one and two mole of potassium tert-butoxide has been studied and the mechanism of the product formation is discussed with regard to either an allene or alkyne as a possible intermediate.