title: Metal-Free Allene-Based Synthesis of Enantiopure Fused Polycyclic Sultones.
abstract: The controlled metal-free preparation of fused δ-sultone derivatives has been developed starting from hydroxyallenynes. The use of 2-(3,3-diethyltriaz-1-enyl)-4-methylbenzene-1-sulfonyl chloride in a sulfonylation/rearrangement sequence gives access to 1,3-dien-2-yl arenesulfonates. These functionalized enynes suffered a direct cyclization/desaturation radical cascade, allowing the synthesis of a variety of enynyl [1,2]oxathiine 1,1-dioxides. Stereoselective cyclization of the readily formed core through intramolecular Diels-Alder reaction has also been demonstrated, affording β-lactam- and glucofuranoside-fused δ-sultone polycycles. These selective reactions have been studied experimentally and additionally, their reaction mechanisms have been investigated computationally by means of density functional theory calculations.
authors.affiliation: Grupo de Lactamas y Heterociclos Bioactivos, Departamento de Química Orgánica I, Unidad Asociada al CSIC, Facultad de Química, Universidad Complutense de Madrid, 28040 Madrid (Spain). alcaideb@quim.ucm.es.
authors.forename: Benito
authors.initials: B
authors.lastname: Alcaide
authors.affiliation: Instituto de Química Orgánica General, Consejo Superior de Investigaciones Científicas, IQOG-CSIC, Juan de la Cierva 3, 28006 Madrid (Spain). Palmendros@iqog.csic.es.
authors.forename: Pedro
authors.initials: P
authors.lastname: Almendros
authors.affiliation: Grupo de Lactamas y Heterociclos Bioactivos, Departamento de Química Orgánica I, Unidad Asociada al CSIC, Facultad de Química, Universidad Complutense de Madrid, 28040 Madrid (Spain).
authors.forename: Cristina
authors.initials: C
authors.lastname: Aragoncillo
authors.affiliation: Departamento de Química Orgánica I, Facultad de Química, Universidad Complutense de Madrid, 28040 Madrid (Spain).
authors.forename: Israel
authors.initials: I
authors.lastname: Fernández
authors.affiliation: Grupo de Lactamas y Heterociclos Bioactivos, Departamento de Química Orgánica I, Unidad Asociada al CSIC, Facultad de Química, Universidad Complutense de Madrid, 28040 Madrid (Spain).
authors.forename: Gonzalo
authors.initials: G
authors.lastname: Gómez-Campillos
keywords: allenes; cyclization; density functional calculations; radicals; sulfur heterocycles