Total synthesis of (+)-isoschizandrin utilizing a samarium (II) iodide-promoted 8-endo ketyl-olefin cyclization

GA Molander, KM George…

Index: Molander, Gary A.; George, Kelly M.; Monovich, Lauren G. Journal of Organic Chemistry, 2003 , vol. 68, # 25 p. 9533 - 9540

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Citation Number: 101

Abstract

The 13-step synthesis of (+)-isoschizandrin reported herein features a samarium (II) iodide- promoted 8-endo ketyl-olefin coupling to assemble the eight-membered ring present in the target concomitantly with the required functionality and stereochemistry. In constructing (+)- isoschizandrin as a single atropisomer, the synthesis utilizes a kinetic resolution of a seven- membered lactone using a CBS-oxazaborolidine.