Cleavage of the oxygen bridge in 8-oxabicyclo[3.2.1]octanes by reductive elimination

Several 2(4)-bromo- or chloro-8-oxabicyclo[3.2.1]oct-6-en-3-ones (2), available by [4+3] cycloaddition of monohalogeno-oxyallyl intermediates with furans, were reduced to halogenated 8-oxabicyclo[3.2.1]oct-6-en-3endo-ols (6) and saturated analogues (7). Cycloheptene-1,3trans-diols (8,11) were formed preferentially by reductive elimination.