A five-step, highly efficient synthesis of tetrahydrofurobenzofuran 2,
the pivotal intermediate in the synthesis of aflatoxin B2, has been a
chieved in 24% (40% on the basis of the recovered aldehyde for the Wit
tig conversion of 5a to 4a) overall yield from 5a. The key chain-branc
hing step that provided the tetrahydobisfuran carbon framework has bee
n achieved by use of the Kikuchi rearrangement reaction, i.e., treatme
nt with I2, Ag2O, dioxane/H2O of the styrene system 4b.