Stereoselective synthesis of cyclic ethers using vinylogous sulfonates as radical acceptors: effect of E/Z geometry and temperature on diastereoselectivity
PA Evans, T Manangan
文献索引：Evans, P Andrew; Manangan, Thara Journal of Organic Chemistry, 2000 , vol. 65, # 15 p. 4523 - 4528
Treatment of the E-vinylogous sulfonates 1a-g with tris (trimethylsilyl) silane and triethylborane, in the presence of air, furnished the cyclic ethers 2/3a-g with good to excellent diastereoselectivity favoring the cis-isomer 2. This study demonstrated the level of stereocontrol in a 6-exo radical cyclization and may be attributed to the type of radical intermediate. Hence, the modest selectivity obtained for the cyclization of 1e may be a ...
