Tandem vinylcyclopropane ring opening/Prins cyclization for the synthesis of 2,3-disubstituted tetrahydropyrans
作者:B.V. Subba Reddy、V. Swathi、Manika Pal Bhadra、M. Kanaka Raju、A.C. Kunwar
DOI:10.1016/j.tetlet.2016.03.062
日期:2016.4
An efficientsynthesis of 2,3-disubstituted tetrahydropyransfrom aldehyde and cyclopropyl alkenol has been accomplished using HBF4·OEt2 as a promoter through a tandem vinylcyclopropane ring-opening/Prinscyclization. It is a convenient process to generate a structurally diverse and biologically relevant 2,3-disubstituted tetrahydropyrans in good yields with high selectivity.
Atom-economical cobalt-catalysed regioselective coupling of epoxides and aziridines with alkenes
作者:Gabriele Prina Cerai、Bill Morandi
DOI:10.1039/c6cc04410g
日期:——
An atom-economical cobalt-catalysed regioselective coupling of epoxides and aziridines with alkenes is reported.
报道了一种原子经济的钴催化的选择性区域偶联环氧化物和环氧丙烷与烯烃。
5-(Methylthio)tetrazoles as versatile synthons in the stereoselective synthesis of polycyclic pyrazolines via photoinduced intramolecular nitrile imine–alkene 1,3-dipolar cycloaddition
作者:Daniel Pla、Derek S. Tan、David Y. Gin
DOI:10.1039/c4sc00107a
日期:——
A key thioether substituent in readily accessible 2-alkyl-5-(methylthio)tetrazoles enables facile photoinduced denitrogenation and intramolecularnitrileimine 1,3-dipolar cycloaddition to afford a wide range of polycyclic pyrazoline products with excellent diastereoselectivity. The methylthio group red-shifts the UV absorbance of the tetrazole, obviating the requirement in all previous substrate systems
Iodocyclization/base-induced hydrodeiodination reaction of 5-substituted 4-alkenols. The influence of substituent on the stereoselective pathway
作者:Claudio Paolucci、Paolo Righi
DOI:10.1016/j.tet.2007.09.074
日期:2007.12
erythro-2-(1-iodo-2,2-dimetylpropyl)tetrahydrofuran with high stereoselectivity. The threo isomer gave clean formation of 6-tert-butyl-3,4-dihydro-2H-pyran by base-induced ring expansion, while erythro isomer underwent a base-induced ring contraction to 1-cyclopropyl-3,3-dimethylbutan-1-one. Moreover, (Z)- and (E)-5-cyclopropylpent-4-en-1-ol underwent a 6-endo-iodocyclization to threo- and erythro-2-cyclopropyl