4376-83-4Relevant academic research and scientific papers
TFA-mediated tandem Friedel-Crafts alkylation/cyclization/hydrogen transfer process for the synthesis of flavylium compounds
Wu, Yan-Chao,Liu, Li,Liu, Yu-Liang,Wang, Dong,Chen, Yong-Jun
, p. 9383 - 9386 (2008/03/13)
(Chemical Equation Presented) The tandem reaction of phenols and chalcones in refluxing TFA gave the flavylium species of 2-hydroxy-2-phenyl-2H-chromenes in moderate to good isolated yields. The reaction was proposed to involve a tandem transformation of
Reaction of 3-Halogeno-2H-1-benzopyran-2-ones with Organometallic Compounds. Synthesis of 4-Alkyl-2H-1-benzopyran-2-ones. X-Ray Molecular Structure of 3-Bromo-3,4-dihydro-4-isopropylcoumarin
Alberola, Angel,Calvo, Blanca,Ortega, Alfonso Gonzalez,Vicente, Martina,Granda, Santiago G.,Van der Maelen, Juan F.
, p. 203 - 210 (2007/10/02)
3-Halogeno-2H-1-benzopyran-2-ones react with magnesium, lithium, aluminium and copper derivatives to give 3,4-dihydrocuomarins and 3-(o-hydroxyphenyl)propenols as major products.The nature and the ratio of the products in the final mixture depend on the solvent and on the organometallic reagent.Grignard derivatives yield 1,4-monoalkylation compounds in tetrahydrofuran (THF) or 1,2-dialkylation derivatives in toluene.In some cases the dehalogenation competes with the 1,2-alkylation process in the reactions with alkyllithiums.The presence of the halogen at C-3 increases the reductive ability of organoaluminiums.In general, the reaction with lithium dialkylcuprates leads to complex mixtures of products.The 4-alkyl-3-halogeno-3,4-dihydrocuomarins obtained undergo dehydrohalogenation easily, and lead to 4-alkylcuomarins in good yields.The tandem alkylation-dehydrohalogenation of 3-halogeno-2H-1-benzopyran-2-ones constitutes a versatile synthesis of 4-alkylcuomarins.
