α-Clausenan [3-methyl-2-(3-methyl-1,3-butadienyl)furan], which is found in Clausena willdenovii, was synthesized by starting from methyl 3-(3-methyl-2-furanyl)propionate in a 34% overall yield in 4 steps.
Unexpected regiocontrol in the Pauson–Khand reaction due to 2-furyl substitution of the alkene component
作者:Laurence M. Harwood、Lucía San Andrés Tejera
DOI:10.1039/a703786d
日期:——
2-Vinylfuran derivatives undergo regiocontrolled PausonâKhand
reaction, in which the furan exerts the dominant directing influence, to
furnish 5-(2-furyl)cyclopent-2-enones, overwhelming the strong directing
effects of a homoallylic thioether and appearing to inhibit intramolecular
reaction in which bridging constraints are in opposition to the directing
influence of the 2-furyl substituent.