Alkene substituents for selective activation of endo-regioselective polyepoxide oxacyclizations.
The presence of an alkenyl substituent on the terminal epoxide of a polyepoxide substrate enhances the yield of all-endo-regioselective tandem oxacyclization to trans-syn-trans-fused polycyclic ethers. For a substrate in which the epoxide and alkene functional groups are separated by two methylene substituents, a novel bromonium ion-induced endo-regioselective cyclization to bromooxepane is also described. [reaction: see text]
Bravo
Fernando
F
Department of Chemistry, Emory University, Atlanta, GA 30322, USA.
McDonald
Frank E
FE
Neiwert
Wade A
WA
Hardcastle
Kenneth I
KI
D000475:Alkenes / Q000737:chemistry*; D003500:Cyclization; D004852:Epoxy Compounds / Q000737:chemistry*; D011083:Polycyclic Compounds / Q000138:chemical synthesis*
D000475:Alkenes; D004852:Epoxy Compounds; D011083:Polycyclic Compounds