Triflic Acid-Mediated Rearrangements of 3-Methoxy-8-oxabicyclo[3.2.1]octa-3,6-dien-2-ones: Synthesis of Methoxytropolones and Furans
作者:Yvonne D. Williams、Christine Meck、Noushad Mohd、Ryan P. Murelli
DOI:10.1021/jo401617r
日期:2013.12.6
because of their known biological activity and established value in the synthesis of α-hydroxytropolones. Upon treatment with triflic acid, a series of 3-methoxy-8-oxabicyclo[3.2.1]octa-3,6-dien-2-ones rearrange rapidly and cleanly to form methoxytropolones. Interestingly, bicycles that are derived from dimethyl acetylenedicarboxylate (R2 = R3 = CO2Me) instead form furans as the major product.
甲氧基托酚酮是用于治疗开发的有用支架,因为其已知的生物活性和在 α-羟基托酚酮合成中的确定价值。用三氟甲磺酸处理后,一系列 3-甲氧基-8-氧杂二环[3.2.1]八-3,6-二烯-2-酮快速而干净地重排,形成甲氧基托酚酮。有趣的是,衍生自乙炔二甲酸二甲酯(R 2 = R 3 = CO 2 Me)的自行车反而形成呋喃作为主要产物。
A Mild, Convenient and Efficient Single-Step Method for the Synthesis of Polysubstituted Furans via Ammonium Ylide Routes
作者:Yongmin Liang、Mingjin Fan、Lina Guo、Xueyuan Liu、Weimin Liu
DOI:10.1055/s-2004-834944
日期:——
A new and convenient cyclization method for the synthesis of polysubstituted furans in a single-step via ammonium ylide routes was reported. In this process, dimethyl acetylenedicarboxylate reacted with ammonium ylide to produce polysubstituted furan in the presence of anhydrous K2CO3 at room temperature. It is very economical, environmentally friendly and very easy to carry out.
Studies dealing with the excited-state behavior of substituted 8-oxabicyclo[3.2.1]oct-6-en-2-ones
作者:Albert Padwa、Lin Zhi、Glen E. Fryxell
DOI:10.1021/jo00003a032
日期:1991.2
A series of 8-oxabicyclo [3.2.1]oct-6-en-2-ones was prepared by the rhodium(II)-catalyzed cyclization-cycloaddition reaction of alpha-diazopentanedione with various alkynes. The photochemical behavior of these oxabicyclic enones was investigated. Both direct and sensitized photolysis cleanly results in a 1,3-acyl shift. A slower, secondary photoprocess involving intramolecular hydrogen atom transfer and intramolecular cycloaddition of the resulting ketene was also uncovered. The photobehavior of the closely related 9-oxabenzocycloheptene system was also examined. The initially formed 1,3-sigmatropic rearranged product was found to undergo a novel 1,4-methoxyl migration on extended photolysis. The photochemistry of the homologous 7-oxabicyclo[2.2.1]hepten-2-one was studied. The results obtained can be interpreted in terms of an initial Norrish type I cleavage. The resulting diradical either couples to give the 1,3-acyl shift product or undergoes bond fragmentation, giving products derived from a stepwise retro-Diels-Alder reaction.
MEDVEDSKAYA L. B.; KONDRATEVA G. YA.; BYKANOVA N. V., IZV. AN CCCP. CEP. XIM., 1979, HO 7, 1613-1615
作者:MEDVEDSKAYA L. B.、 KONDRATEVA G. YA.、 BYKANOVA N. V.