In the presence of In/CuCl, ethyl 4-bromo-4,4-difluoro-3-oxo-2-(triphenylphosphoranylidene)butanoate reacted with various aldehydes in aqueous medium at room temperature to give the a,a-difluorinated β-hydroxy carb...In the presence of In/CuCl, ethyl 4-bromo-4,4-difluoro-3-oxo-2-(triphenylphosphoranylidene)butanoate reacted with various aldehydes in aqueous medium at room temperature to give the a,a-difluorinated β-hydroxy carbonyl compounds. Furthermore, treating Reformatsky addition compounds with 1 equiv, of sodium hydroxide in the mixture of tetrahydrofuran and water afforded gem-difluoromethylenated 2-triphenylphosphoranylidene δ-lactones in excellent yields.展开更多
Treatment of chiral N-tert-butyl sulfinylimines with ethyl bromofluoroacetate in the presence of activated Zn dust in THF afforded the α-fluoro- β-amino acid derivatives in good yields(70-86%) and moderate diaster...Treatment of chiral N-tert-butyl sulfinylimines with ethyl bromofluoroacetate in the presence of activated Zn dust in THF afforded the α-fluoro- β-amino acid derivatives in good yields(70-86%) and moderate diastereoselectivity(66:34-92:8).展开更多
A new facile route for the synthesis of dl-shikonin is presented. Reformatsky reaction assisted cross-coupling of 1, 4, 5, 8-tetramethoxynaphthalene-2-carbaldehyde and ethyl- bromoacetate was employed for introductio...A new facile route for the synthesis of dl-shikonin is presented. Reformatsky reaction assisted cross-coupling of 1, 4, 5, 8-tetramethoxynaphthalene-2-carbaldehyde and ethyl- bromoacetate was employed for introduction of the side chain of dl-shikonin.展开更多
基金Project supported by the National Natural Science Foundation of China (NNSFC) (Nos. 20972050, 21172148).
文摘In the presence of In/CuCl, ethyl 4-bromo-4,4-difluoro-3-oxo-2-(triphenylphosphoranylidene)butanoate reacted with various aldehydes in aqueous medium at room temperature to give the a,a-difluorinated β-hydroxy carbonyl compounds. Furthermore, treating Reformatsky addition compounds with 1 equiv, of sodium hydroxide in the mixture of tetrahydrofuran and water afforded gem-difluoromethylenated 2-triphenylphosphoranylidene δ-lactones in excellent yields.
基金The Shanghai Pujiang Program(No.09PJ 1400800)the Fundamental Research Funds for the Central Universities are greatly acknowledged for funding this work
文摘Treatment of chiral N-tert-butyl sulfinylimines with ethyl bromofluoroacetate in the presence of activated Zn dust in THF afforded the α-fluoro- β-amino acid derivatives in good yields(70-86%) and moderate diastereoselectivity(66:34-92:8).
文摘A new facile route for the synthesis of dl-shikonin is presented. Reformatsky reaction assisted cross-coupling of 1, 4, 5, 8-tetramethoxynaphthalene-2-carbaldehyde and ethyl- bromoacetate was employed for introduction of the side chain of dl-shikonin.