Synthesis of prostaglandin and phytoprostane B1 via regioselective intermolecular Pauson-Khand reactions.
A new approach to the synthesis of prostaglandin and phytoprostanes B(1) is described. The key step is an intermolecular Pauson-Khand reaction between a silyl-protected propargyl acetylene and ethylene. This reaction, promoted by NMO in the presence of 4 A molecular sieves, afforded the 3-tert-butyldimethylsilyloxymethyl-2-substituted-cyclopent-2-en-1-ones (III) in good yield and with complete regioselectivity. Deprotection of the silyl ether, followed by Swern oxidation, gave 3-formyl-2-substituted-cyclopent-2-en-1-ones (II). Julia olefination of the aldehydes II with the suitable chiral sulfone enabled preparation of PPB(1) type I and PGB(1).
Vázquez-Romero
Ana
A
Unitat de Recerca en Síntesi Asimètrica (URSA-PCB), Institute for Research in Biomedicine Universitat de Barcelona, Parc Cientific de Barcelona c/ Baldiri Reixac 10, 08028 Barcelona, Spain.
Cárdenas
Lydia
L
Blasi
Emma
E
Verdaguer
Xavier
X
Riera
Antoni
A
D003517:Cyclopentanes / Q000138:chemical synthesis / Q000737:chemistry; D005231:Fatty Acids, Unsaturated / Q000138:chemical synthesis* / Q000737:chemistry; D005663:Furans / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D011453:Prostaglandins / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
D003517:Cyclopentanes; D005231:Fatty Acids, Unsaturated; D005663:Furans; D011453:Prostaglandins; C500684:phytoprostane B1 type I