Intramolecular sensitization within steroids: Excited-state interaction of C-17 alpha and beta carbon-bromine bonds with a C-6 carbonyl group

Li W., Torun L., Morrison H.

CANADIAN JOURNAL OF CHEMISTRY, cilt.81, sa.6, ss.660-668, 2003 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 81 Sayı: 6
  • Basım Tarihi: 2003
  • Doi Numarası: 10.1139/v03-055
  • Dergi Adı: CANADIAN JOURNAL OF CHEMISTRY
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.660-668
  • Yıldız Teknik Üniversitesi Adresli: Hayır

Özet

The synthesis, photochemistry, and photophysics of 17alpha-bromo-3alpha-(triphenylsilyloxy)-5alpha-androstan-6-one (1) and 17beta-bromo-3beta-(triphenylsilyloxy)-5alpha-androstan-6-one (2) have been studied in aqueous tetrahydrofuran. The 17alpha-bromo isomer gives evidence (reduced phi(f), tau(1), and phi(isc) for the ketone) for interaction between the ketone and C-Br moieties in the excited singlet state. Some photodehalogenation is also observed upon excitation of the ketone chromophore. This interaction seems to be absent or minimal for the 17beta-bromo isomer.