De. Shaw et al., A RADICAL CYCLIZATION APPROACH TO THE 2-OXABICYCLO[2.2.1]HEPTANE RING-SYSTEM, Journal of the Chemical Society, Chemical Communications, (21), 1994, pp. 2447-2448
Intramolecular cyclisations of radicals generated from the beta-substi
tuted tetrahydrofurans 6, 7 and 14c onto suitably positioned alkene fu
nctions attached to the alpha'-position of the heterocycle give good t
o excellent yields of the 2-oxabicyclo[2,2,1]heptanes 8, 9 and 16.