Diastereoselective [4 + 4]-Photocycloaddition Reactions of Pyran-2-ones: Rapid Access to Functionalized 5−8−5 Skeletons
作者:Dong Song、Robert McDonald、F. G. West
DOI:10.1021/ol061576h
日期:2006.8.1
Fused bicyclic pyran-2-ones with pendant furan side chains and an oxygenated stereogenic center adjacent to the pyranone ring oxygen were prepared via FeCl3-catalyzed Michael addition. Irradiation furnished the corresponding lactone-bridged tricyclic [4+4]-cycloadducts with good facial selectivity. Surprisingly, the major isomer resulted from approach of the furan from the same face as the protected alcohol.