Synthesis of demethylated nidulol via an intramolecular Michael reaction.
An expeditious synthesis of 5,7-dihydroxy-6-methylphthalide from open-chain precursors is described. The key intermediates, synthons 3 and 4, were readily obtained from accessible materials and were further transformed to a common precursor, a five-membered lactone derivative, via an intramolecular Michael addition. Lactone 2 was aromatised to the phthalide system under basic conditions. The process thus constitutes a formal synthesis of the phthalide framework.
Jimenez
Rogelio
R
Departamento de Quimica Organica, Escuela Nacional de Ciencias Biologicas, Instituto Politecnico Nacional, Prolongacion Carpio y Plan de Ayala S/N, Mexico. rogelio_jj48@yahoo.com.mx
Maldonado
Luis A
LA
Salgado-Zamora
Hector
H
D001572:Benzofurans / Q000138:chemical synthesis* / Q000737:chemistry; D007783:Lactones / Q000737:chemistry; D015394:Molecular Structure; D010796:Phthalic Anhydrides / Q000138:chemical synthesis*; D013055:Spectrophotometry, Infrared
D001572:Benzofurans; D007783:Lactones; D010796:Phthalic Anhydrides; C082022:phthalide