title: Synthesis of Antitumor Lycorines by Intramolecular Diels-Alder Reaction.
abstract: Pharmacologically interesting lycorines were obtained by a short, efficient method based on an intramolecular Diels-Alder reaction between an alpha-pyrone and an alkyne, followed by loss of CO(2) in a retro Diels-Alder reaction. The cyclization precursors (pyrones 9) were obtained in good yields in two or three steps from the corresponding homophthalic acid or anhydride.
authors.affiliation: Departamento de Química Orgánica, Universidad de Santiago, and Sección de Alcaloides del CSIC, 15706 Santiago de Compostela, Spain.
authors.forename: Dolores
authors.initials: D
authors.lastname: Pérez
authors.forename: Gema
authors.initials: G
authors.lastname: Burés
authors.forename: Enrique
authors.initials: E
authors.lastname: Guitián
authors.forename: Luis
authors.initials: L
authors.lastname: Castedo