SmI2-induced cyclization of (E)- and (Z)-β-alkoxyvinyl sulfones with aldehydes
摘要:
SmI2-induced reaction of (E)- and (Z)-beta-alkoxyvinyl sulfones onto an aldehyde function afforded 2,6-syn-2,3-trans- and 2,6-syn-2,3-cis-tetrahydropyran-3-ols, respectively, via stereoselective cyclization. This reaction was applied to the synthesis of 2-methyl-tetrahydropyran, corresponding to the N-ring of gymnocin-A, and 2-exo-methylene-tetrahydropyran, a key intermediate for convergent synthesis of polycyclic ethers based on the Suzuki-Miyaura reaction. (C) 2010 Elsevier Ltd. All rights reserved.