86728-40-7Relevant academic research and scientific papers
Studies Directed toward the Total Synthesis of Securinega Alkaloids
Heathcock, Clayton H.,Jennings, Rex A.,von Geldern, Thomas W.
, p. 3428 - 3431 (1983)
An approach to the synthesis of securinega alkaloids is reported.Reductive amination of ethyl-2-thienylacetoacetate (12) with methyl (S)-prolinate gives a mixture of diastereomeric amino diesters 6 and 13 in a ratio of 44:56.Dieckmann cyclization of the mixture followed by treatment of the product with acid affords the crystalline (+/-)-10 in 64percent yield.Separation of 6 and 13 prior to cyclization provides samples of the enantiomers (-)-10 and (+)-10, respectively.Attempts to open the thiophene ring of 10 were not successful.Treatment of (+/-)-10 with excess n-butyllithium and trimethylsilyl chloride results in a novel fragmentation, leading to the benzothiophene 18.
Non-metal Lewis acid-catalyzed cross-Claisen condensation for β-keto esters
Han, Zhengyu,Huang, Hai,Meng, Fuliang,Yang, Zhenkun,Zhang, Tianyu,Zhou, Dapeng
supporting information, p. 9163 - 9166 (2021/11/16)
In this work, we disclose a new catalytic and highly chemoselective cross-Claisen condensation of esters. In the presence of TBSNTf2 as a non-metal Lewis acid, various esters can undergo cross-Claisen condensation to form β-keto esters which are important building blocks. Compared with the traditional Claisen condensation, this process, employing silyl ketene acetals (SKAs) as carbonic nucleophiles to achieve cross-Claisen condensation, requires mild conditions and has good tolerance of functional groups. This journal is
Hauser-Heck: Efficient Synthesis of γ-Aryl-β-ketoesters en Route to Substituted Naphthalenes
Wagner, Frederic,Harms, Klaus,Koert, Ulrich
supporting information, p. 5670 - 5673 (2015/12/08)
γ-Aryl-β-ketoesters can be prepared in one step from aryl bromides and bis(trimethylsilyl) enol ethers using catalytic amounts of Pd(dba)2/t-Bu3P and stoichiometric amounts of Bu3SnF. The wide range of γ-(hetero)aryl-β-ketoesters that can be obtained illustrate the scope and limitations of this novel Hauser-Heck combination. γ-Aryl-β-ketoesters with a 1,3-dioxane acetal in the ortho position can easily be transformed into the hydroxy naphthoate in very good yield. Aqueous formic acid at 65 °C provides optimal conditions for this deprotective aromatization.
