G. Ap-pendino, G. Cravotto, L. Toma, R. Annunziata and G. Palmisano, “The Chemistry of Coumarin Derivatives. Part VI. Diels-Alder Trapping of 3-Methylene-2,4-chromandione. A New Entry to Substituted Pyrano[3,2-c] cou- marins,” Journal of Organic Chemistry, Vol. 59, No. 19, 1994, pp. 5556- 5564.

has been cited by the following article:

• TITLE: SO42-/SnO2-Catalyzed C3-alkylation of 4-hydroxycoumarin with secondary benzyl alcohols and O-alkylation with O-acetyl compounds

  AUTHORS: Venugopalarao Narayana, Ravi Varala, Pudukulathan Zubaidha

  KEYWORDS: C-C and C-O bond formations, Sulfated tin oxide (STO), reusability, 4-Hydroxy coumarin, secondary benzyl alcohol, secondary benzyl O-acetate

  JOURNAL NAME: International Journal of Organic Chemistry, Vol.2 No.3A, October 3, 2012

  ABSTRACT: Sulfated tin oxide (STO) has been found to be an efficient reusable solid superacid catalyst for C3-alkylation and O-alkylation of 4-hydroxycoumarins with benzylic, allylic alcohols/and corresponding acetates respectively, in acetic acid under reflux conditions with good yield of products.