Conformational bias in macrocyclic ethers and observation of high solvolytic reactivity at a masked furfuryl (=2-furylmethyl) C-atom


Guella G., Mancinci I., Oztunc A., Pietra F.

HELVETICA CHIMICA ACTA, cilt.83, ss.336-348, 2000 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 83 Konu: 2
  • Basım Tarihi: 2000
  • Dergi Adı: HELVETICA CHIMICA ACTA
  • Sayfa Sayıları: ss.336-348

Özet

New polyhalogenated, twelve-membered. O-bridged cyclic C-15-ethers. having in common oxygenation at C(6) and a bromoallene side chain at C(4) (where C(1) is the bromoallene-chain terminus). were isolated from the red seaweed Laurencia obtusa from the Turkish Mediterranean Sea. i.e. the: 9.12-O-bridged obtusallene VII (5). the 6.9 :9.12-bis-O-bridged obtusallene V (3) and obtusallene VI (4), as well as the 6,9-O-bridged obtusallene VIII (8) and obtusallene IX (9). The behaviour of portions of the macrocycle involved in fast motion and their equilibrium position depend on the particular compound, revealing a sub;lc. conformational behavior of these macrocycles, while 8 and 9 show an unprecedented solvolytic reactivity at the masked furfuryl (-2- furyimethyl) C-atom.