Facile Synthesis of Imidazo[1,5-a]pyrazin-8(7H)-ones from Mesoionic 1,3-Oxazolium-5-olates via a Multistep One-Pot Transformation
摘要:
A novel one-pot conversion of mesoionic 4-trifluoroacetyl-1,3-oxazolium-5-olates into imidazo[1,5-a]pyrazin-8(7.H)-ones by the reaction with TosMIC is described. The structure of the product was determined by single-crystal X-ray analysis.
New Synthesis of 3-Trifluoromethylpyrroles by Condensation of Mesoionic 4-Trifluoroacetyl-1,3-oxazolium-5-olates with Phosphorus Ylides
作者:Ryosuke Saijo、Yuri Hagimoto、Masami Kawase
DOI:10.1021/ol1018689
日期:2010.11.5
Mesoionic 4-trifluoroacetyl-1,3-oxazolium-5-olates (1), obtained from the reaction of N-acyl-N-alkylglycines with trifluoroacetic anhydride, react with phosphorus ylides to give beta-trifluoromethylpyrroles (2) in good yields. The novel ring transformations of 1 into 2 occur via an initial attack of the ylide anions on the C-2 position of the ring.