A facile route to 3a,8a-dihydrofuro[2,3-b]benzofurans
摘要:
Consecutive employment of palladium-catalysis and samarium(II)iodide-induced radical chemistry allows access to analogues of the ABC enol ether tricycle of aflatoxin B-1 (1). The Pd-assisted coupling of tribulylstannyl ethers of various 2-iodophenols with 2,5-diacetoxy-2,5-dihydrofuran (4) provided products that could be cyclised into 3a,8a-dihydrofuro[2,3-b]benzofurans using SmI2. Elimination of an acetatosamarium species provides the requisite unsaturation in situ.