The 1,3-dibromo-5,5-dimethylhydantoin (DBH) was found to efficiently catalyze the one-pot synthesis of highly functionalized tetrasubstituted furan derivatives by the reaction of 1,4-diarylbut-2-ene-1,4-diones and acetoacetates in i-PrOH as the solvent at 80 -908 for 3 -7 h. The products were formed in high yields (82 -95%) under mild and neutral conditions.Introduction. -Substituted furan derivatives are important synthetic intermediates [1] and are found as structural units in many natural products such as in kallolides [2], cembrenolides [3], pheromones [4], and polyether antibiotics [5]. These heterocycles have found applications in many pharmaceuticals, fragrances, and dyes [6]. Furan subunits have also been used as building blocks for a large number of heterocyclic compounds and as synthons in natural-product synthesis [7]. As a consequence, the synthesis [8 -11] and the applications [12 -15] of furan derivatives still attract the attention of organic chemists. The most common strategy involved in the synthesis of furans is the cyclization [16] of 1,4-dicarbonyl compounds. Of the various other methods, syntheses involving transition-metal salts have recently been described for the preparation of substituted furan derivatives [17]. Oh and co-workers [18] have synthesized highly substituted furans via Pt-catalyzed hydroxy-or alkoxy-assisted cyclization of 2-(alk-1-yn-1-yl)alk-2-en-1-ones. More recently, Jaisankar and coworkers reported a novel method for the preparation of highly substituted furans by InCl 3 -catalyzed nucleophilic addition followed by a cyclization reaction, although it was limited to specific substrate classes [19].

N-Bromosuccinimide was found to efficiently catalyze the synthesis of highly functionalized, tetra-substituted furan derivatives in the one-pot reactions of but-2-ene-1,4-diones and acetoacetate esters in the presence of i-PrOH as solvent under mild and neutral conditions at 80-90?C for 3-7 h in high yields (87-94%).

Furan derivatives R 0060Efficient One-Pot 1,3-Dibromo-5,5-dimethylhydantoin (DBH)-Catalyzed Synthesis of Highly Substituted Furans. -An advantage is the better yield of products compared with previously reported methods. In addition, the catalyst is inexpensive and not moisture-sensitive. -(GHASEMNEJAD*-BOSRA*, H.; FARAJE, M.; HABIBZADEH, S.; Helv. Chim. Acta 92 (2009) 3, 575-578; Dep. Chem., Sch. Sci., Islamic Azad Univ. Babol, Babol, Iran; Eng.) -Bartels 29-100

N-Bromosuccinimide was found to efficiently catalyze the sy nthesis of highly functionalized, tetra-substituted fura n derivative s in the one-pot reactions of but-2-ene-1,4-diones and acetoacetate esters in the presence of i-PrOH as solvent u nder mild and neutral conditi ons at 8 0-90 °C f or 3-7 h in hi gh yields (87-94 %).