New chiral synthons for efficient introduction of bispropionates via stereospecific oxonia-cope rearrangements.
Compounds 1 and 2 are novel synthons for bispropionate synthesis, undergoing stereospecific Lewis acid-catalyzed transfer of the bispropionate unit with a variety of aldehydes, including alpha-chiral aldehydes. Thus 1 leads to the E-alkene bispropionate 3 with anti-stereochemistry, whereas diastereomer 2 gives the Z-alkene product 4, under mild conditions and with complete stereospecificity. The efficacy of this methodology is demonstrated in a short synthesis of invictolide beginning with 2 and (R)-2-methylpentanal.
Chen
Yi-Hung
YH
Department of Chemistry, Emory University, Atlanta, Georgia 30322, USA.
McDonald
Frank E
FE
D000085:Acetates / Q000737:chemistry*; D000447:Aldehydes / Q000737:chemistry; D004164:Diphosphonates / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000737:chemistry*; D011422:Propionates / Q000138:chemical synthesis / Q000737:chemistry*; D011753:Pyrones / Q000138:chemical synthesis / Q000737:chemistry*; D013237:Stereoisomerism
D000085:Acetates; D000447:Aldehydes; D004164:Diphosphonates; C118890:Oxonia Active; D011422:Propionates; D011753:Pyrones; C559840:invictolide; D006861:Hydrogen Peroxide