Stereopentads derived from a sequence of Mukaiyama aldolization and free radical reduction on alpha-methyl-beta-alkoxy aldehydes: a general strategy for efficient polypropionate synthesis.
In a stereodivergent manner, all 16 diastereomeric stereopentads 7-22 were synthesized starting with alpha-methyl-beta-alkoxy aldehydes 25 and 27. We designed an approach based on a sequence of a Mukaiyama aldolization with enoxysilane 24 followed by a hydrogen transfer reaction. Recent advancements concerning these reactions are described, and novel key intermediates are characterized in the aldol step. The synthesis of C(1)-C(11) fragment 60 of zincophorin, which contains a synthetically challenging stereopentad unit, is described attesting the usefulness of our strategy.
Brazeau
Jean-François
JF
Institut de recherches cliniques de Montréal, Bio-organic Chemistry Laboratory, 110 Avenue des Pins Ouest, Montréal, Québec, Canada H2W 1R7.
Mochirian
Philippe
P
Prévost
Michel
M
Guindon
Yvan
Y
D000447:Aldehydes / Q000737:chemistry*; D018360:Crystallography, X-Ray; D005609:Free Radicals / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008968:Molecular Conformation; D010084:Oxidation-Reduction; D011422:Propionates / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
D000447:Aldehydes; D005609:Free Radicals; D011422:Propionates; C116609:3-hydroxybutanal