title: Synthesis of 1-methyl-3-oxo-7-oxabicyclo[2.2.1]hept-5-ene-2-carboxylic acid methyl ester.
abstract: A simple and efficient method for the preparation of 1-methyl-3-oxo-7- oxabicyclo[2.2.1]hept-5-en-2-carboxylic acid methyl ester (1) is described. The first step is a highly regioselective Diels-Alder reaction between 2-methylfuran and methyl-3-bromo- propiolate. A remarkably difficult ketal hydrolysis reaction was effected by treatment with HCl, a simple reagent that was shown to be more efficient, in this case, than commonly used more elaborate methods.
authors.affiliation: Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Avenida dos Bandeirantes, 3900, 14040-901, Ribeirão Preto, SP, Brazil. varagao@usp.br
authors.forename: Valquiria
authors.initials: V
authors.lastname: Aragão
authors.forename: Mauricio Gomes
authors.initials: MG
authors.lastname: Constantino
authors.forename: Adilson
authors.initials: A
authors.lastname: Beatriz
authors.forename: Gil Valdo
authors.initials: GV
authors.lastname: José da Silva
mesh_terms: D001643:Bridged Bicyclo Compounds / Q000138:chemical synthesis* / Q000737:chemistry*; D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000138:chemical synthesis* / Q000737:chemistry; D002264:Carboxylic Acids / Q000737:chemistry*; D002384:Catalysis; D004952:Esters / Q000138:chemical synthesis* / Q000737:chemistry; D006868:Hydrolysis; D015394:Molecular Structure; D013237:Stereoisomerism
chemical_list: C525121:1-methyl-3-oxo-7-oxabicyclo(2.2.1)hept-5-ene-2-carboxylic acid methyl ester; D001643:Bridged Bicyclo Compounds; D019086:Bridged Bicyclo Compounds, Heterocyclic; D002264:Carboxylic Acids; D004952:Esters