Synthetic efforts toward the spiroketal core of spirangien A.
Synthetic studies toward the spiroketal core of spirangien A are described. Two synthetic approaches were developed. Both of them use a diastereoselective aldol addition of a lithium enolate derived from a methyl ketone on an aldehyde. In the first approach, the introduction of the (E)-trisubstituted terminal olefin was achieved by using an iron-catalyzed cross-coupling between an alkyl iodide and a vinyl Grignard reagent and a randomly protected spiroketal was obtained. In the second approach, a highly functionalized spiroketal carbamate, which includes 13 stereogenic centers, was successfully isolated.
Guérinot
Amandine
A
Laboratoire de Chimie Organique, ESPCI ParisTech, UMR CNRS 7084, 10 rue Vauquelin, 75231 Paris Cedex 05, France.
Lepesqueux
Guillaume
G
Sablé
Serge
S
Reymond
Sébastien
S
Cossy
Janine
J
D000080:Acetals / Q000138:chemical synthesis* / Q000737:chemistry; D002384:Catalysis; D005231:Fatty Acids, Unsaturated / Q000138:chemical synthesis* / Q000737:chemistry; D007501:Iron / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D021241:Spectrometry, Mass, Electrospray Ionization; D013237:Stereoisomerism
D000080:Acetals; D005231:Fatty Acids, Unsaturated; C523683:spirangien A; D007501:Iron