The first directed reduction of beta-alkoxy ketones to anti-1,3-diol monoethers: identification of spectator and director alkoxy groups.
A new reduction procedure for the stereoselective reduction of certain beta-alkoxy ketones is described. The method relies upon electron-transfer reduction using samarium diiodide in THF with MeOH as an additive. Reduction is facile for a number of alkoxy groups that can complex samarium effectively but is not observed with TBS or benzyl protecting groups. Experiments with deuterated methanol show that the stereoselectivity arises from protonation of a samarium carbanion intermediate.
Department of Chemistry, University of Utah, 315 South 1400 East RM 2020, Salt Lake City, Utah 84112-0850, USA. keck@chemistry.utah.edu
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Wager
D003903:Deuterium; D004987:Ethers / Q000138:chemical synthesis* / Q000378:metabolism; D007454:Iodides / Q000378:metabolism; D007659:Ketones / Q000737:chemistry* / Q000378:metabolism; D010084:Oxidation-Reduction; D012493:Samarium / Q000378:metabolism; D013237:Stereoisomerism
D004987:Ethers; D007454:Iodides; D007659:Ketones; D012493:Samarium; D003903:Deuterium; C409809:samarium diiodide