title: Sulphated zirconia as an eco-friendly catalyst in acylal preparation under solvent-free conditions, acylal deprotection assisted by microwaves, and the synthesis of anhydro-dimers of o-hydroxybenzaldehydes.
abstract: A solvent-free approach is described for the regioselective synthesis of acylals (1,1-diacetates) in shorter reaction times and higher yields, compared to conventional methodology using solvents. In the protection reaction of the o-hydroxybenzaldehyde the formation of acetyl compounds and anhydro-dimers was observed. The deprotection reaction involves microwave (MW) exposure of diluted reactants in the presence of solid sulphated zirconia (SZ) catalyst that can be easily recovered and reused. The sulphated zirconia was recycled several times without any loss of activity.
authors.affiliation: Departamento de Ciencias Básicas, UAM-A, Av. San Pablo, No. 180. C.P. 02200, México, D.F., Mexico. lnpg@correo.azc.uam.mx
authors.forename: Laura Nadxieli
authors.initials: LN
authors.lastname: Palacios-Grijalva
authors.forename: Deysi Y
authors.initials: DY
authors.lastname: Cruz-González
authors.forename: Leticia
authors.initials: L
authors.lastname: Lomas-Romero
authors.forename: Eduardo
authors.initials: E
authors.lastname: González-Zamora
authors.forename: Gerardo
authors.initials: G
authors.lastname: Ulibarri
authors.forename: Guillermo E
authors.initials: GE
authors.lastname: Negrón-Silva
mesh_terms: D000812:Anhydrides / Q000138:chemical synthesis*; D001547:Benzaldehydes / Q000138:chemical synthesis*; D002384:Catalysis; D019281:Dimerization; D008872:Microwaves; D012997:Solvents / Q000737:chemistry; D015040:Zirconium / Q000737:chemistry*
chemical_list: D000812:Anhydrides; D001547:Benzaldehydes; D012997:Solvents; D015040:Zirconium; C028541:zirconium oxide