Science Faculty

Abnormal Behaviour of Allenylsulfones under Lu’s Reaction Conditions. Synthesis of Enantiopure Polyfunctionalized Cyclopentenes

Author/s

Núñez Jr., A.; Martín, M. R., Fraile, A.; García Ruano, J. L.

Año de edición

2010

Referencia completa

Chem. Eur. J. 2010, 16, 5443-5453. DOI: 10.1002/chem.200903185

Resumen

Formal [3+2] cycloadditions of 5-alkoxyfuran-2(5H)-ones 1 and 2 with allenylsulfones 3–5, promoted by different nucleophiles, afford 3-alkoxy-5-arylsulfonyl-3,3a,6,6a-tetrahydro-1H-cyclopenta[c]furan-1-ones in good yields with complete control of both regio- and p-facial selectivity. The incorporation of a sulfinyl group on the furanone ring enhances the reactivity of the furanones and allows the synthesis of optically pure, bicyclic adducts in
good yields. Allenylsulfones evolve through a different mechanism to that proposed for allenoates (Lu's reaction) and afford bicyclic adducts in which the sulfonyl group is joined to C-5. This has advantages on the stereochemical control of further reactions leading to enantiomerically pure polyfunctionalised cyclopentenes and cyclopentanes.