Monbaliu, Jean-Christophe ; Université Catholique de Louvain – UCL > Institute of Condensed Matter and Nanosciences > Molecules, Solids and Reactivity (MOST)
Marchand-Brynaert, Jacqueline; Université Catholique de Louvain – UCL > Institute of Condensed Matter and Nanosciences > Molecules, Solids and Reactivity (MOST)
Language :
English
Title :
A practical synthesis of 3-diethoxyphosphoryl-1,2-pyridazine derivatives
(b) Perreux, L.; Loupy, A. Tetrahedron 2001, 57, 9199.
In this case, we supposed that the Lewis acids were quenched by the phosphonate moiety of diene 1, preventing any activation of DTAD. Higher conversion yields observed for the blank than for the Lewis acid activated samples supported this hypothesis. Acids could also contribute to the decomposition of 2c by Boc deprotection.
A few drops of toluene were added to guarantee sufficient fluidity of the reaction mixture. Indeed, the cycloadduct 3c is a viscous oil that precludes stirring of the mixture.
(a) Langa, F.; de la Cruz, P.; de la Hoz, A.; Espildora, E.; Cossio, F.; Lecea, B. J. Org. Chem. 2000, 65, 2499.
(b) Diaz-Ortiz, A.; Carrillo, J.; Cossio, F.; Gomez-Escalonilla, M.; de la Hoz, A.; Moreno, A.; Prieto, P. Tetrahedron 2000, 56, 1569.