Juan Castro
University of Jaén
Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by Juan Castro.
Tetrahedron | 2002
Juan Castro; Sofía Salido; Joaquín Altarejos; Manuel Nogueras; Adolfo Sánchez
Abstract A synthesis of the valuable amber-type odorant Ambrox® from labdanolic acid (main diterpenoid of the acid fraction of non-polar extracts of Cistus ladaniferus L.) is reported. The conversion is based on (a) the α,β-dehydrogenation of methyl labdanolate using an organoselenium reagent, (b) subsequent oxidative degradations of the side chain, and (c) final acid-promoted cyclization of the resulting tetranorlabdan-8α,12-diol. The influence of the temperature and solvent in the cyclization of the diol with p-toluenesulfonic acid is also described. Thus, Ambrox® has been obtained by a six-step procedure in 33% overall yield from methyl labdanolate.
Molbank | 2005
Juan Castro; Ramón Porras; Pablo J. Linares-Palomino; Sofía Salido; Joaquín Altarejos; Manuel Nogueras; Adolfo Sánchez
A 40% aqueous solution of sulfuric acid (0.5 mL) was added to a stirred solution of 3,3-dimethyl- 4-hydroxy-5-(2,2,3-trimethyl-3-cyclopentenyl)-pentan-2-one (1) (630 mg, 2.65 mmol) in methanol (5 mL) and the mixture refluxed for 1.5 h.[...]
Molbank | 2005
Mercedes Pérez-Bonilla; Juan Castro; Pablo J. Linares-Palomino; Joaquín Altarejos; Manuel Nogueras; Adolfo Sánchez; Sofía Salido
p-Toluenesulfonic acid (48 mg, 0.25 mmol) was added to a stirred mixture of ethyl 2-methyl-acetoacetate (1) (346 mg, 2.40 mmol) and a-methylbenzylamine (2) (358 mg, 2.95 mmol) in toluene (13 mL) [1].[...]
Molbank | 2005
Mercedes Pérez-Bonilla; Juan Castro; Pablo J. Linares-Palomino; Sofía Salido; Joaquín Altarejos; Manuel Nogueras; Adolfo Sánchez
Sodium (241 mg, 10.48 mmol) was added to absolute ethanol (40 mL) and the mixture refluxed until sodium reacted completely.
Molbank | 2004
Concepción Badía; Juan Castro; Pablo J. Linares-Palomino; Sofía Salido; Joaquín Altarejos; Manuel Nogueras; Adolfo Sánchez
p-Toluenesulfonic acid (35 mg, 0.20 mmol) was added to a stirred mixture of campholenic aldehyde (1) (725 mg, 3.81 mmol) and p-toluenesulfonamide (1.22 g, 6.96 mmol) in toluene (20 mL).[...]
Molbank | 2004
Concepción Badía; Juan Castro; Pablo J. Linares-Palomino; Sofía Salido; Joaquín Altarejos; Manuel Nogueras; Adolfo Sánchez
Ethyl 2-methylacetoacetate (2) (727 mg, 4.53 mmol) was added to a stirred solution of NaH (184 mg, 4.60 mmol) in dioxane (25 mL).[...]
Molbank | 2004
Juan Castro; Pablo J. Linares-Palomino; Sofía Salido; Joaquín Altarejos; Manuel Nogueras; Adolfo Sánchez
A solution of bromine (0.3 mL, 5.90 mmol) in CCl4 (2 mL) was slowly added over a stirred mixture of 3-methyl-butan-2-one (1) (505 mg, 5.90 mmol) and AcOH (0.33 mL) at room temperature.[...]
Molbank | 2003
Juan Castro; Sofía Salido; Joaquín Altarejos; Manuel Nogueras; Adolfo Sánchez
To a stirred solution of a mixture of E/Z isomers 1 (81 mg, 0.22 mmol, 45:55 ratio) in acetone (5 mL) was added a mixture of KMnO4 (122 mg, 0.77 mmol) and anhydrous MgSO4 (120 mg) at 10 oC [1].[...]
Molbank | 2003
Juan Castro; Sofía Salido; Joaquín Altarejos; Manuel Nogueras; Adolfo Sánchez
To a stirred solution of a mixture of E/Z isomers 1 (174 mg, 0.52 mmol, 45:55 ratio) in acetone (8 mL) was added a mixture of KMnO4 (260 mg, 1.64 mmol) and anhydrous MgSO4 (230 mg) at 10 oC [1].[...]
Molbank | 2003
Juan Castro; Sofía Salido; Joaquín Altarejos; Manuel Nogueras; Adolfo Sánchez
Acetic anhydride (0.53 mL, 5.61 mmol) and N,N-dimethylaminopyridine (17 mg, 0.14 mmol) were added to a stirred solution of the alcohol 1 (442 mg, 1.31 mmol) in freshly distilled triethylamine (1.3 mL) [1].[...]