Synthesis of optically pure di- to tetra-substituted cyclopentanes from sugar-derived norbornene derivatives.
The chiral norbornene derivative 2 obtained from Lewis acid-catalyzed reaction of an L-arabinose-derived dienophile 1 and cyclopentadiene was oxidized with OsO4-NaIO4 to the dialdehyde 3, a tetrasubstituted cyclopentane. Mild treatment of 3 with [Rh(dppp)2]Cl [dppp = Ph2P(CH2)3PPh2] (4) selectively epimerized the aldehyde adjacent to the methoxycarbonyl group to give the epi-aldehyde 8. Under more vigorous conditions, this group was decarbonylated to give the monoaldehyde 11, and more strenuous treatment removed the second aldehyde group to give the didecarbonylated cyclopentane derivative 5. The structure and optical purity of 5 was confirmed by its transformation into (1S,2S)-cyclopentane-1,2-dicarboxylic acid (7).
Horton
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Department of Chemistry, Ohio State University, Columbus 43210.
Usui
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D002241:Carbohydrates / Q000737:chemistry*; D003517:Cyclopentanes / Q000138:chemical synthesis* / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D015394:Molecular Structure; D009636:Norbornanes / Q000737:chemistry; D013237:Stereoisomerism
D002241:Carbohydrates; D003517:Cyclopentanes; D009636:Norbornanes