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Lara BianchiCarlo Dell'Erba Massimo MaccagnoAngelo Mugnoli Marino NoviGiovanni Petrillo Fernando SancassanCinzia Tavani 《Tetrahedron》2003,59(51):10195-10201
1-(Methyl-p-tolyl-amino)-3-phenoxy-2-azetidinones 4-COX and 4-R substituted (COX: X=Me, Et, Ph, NMe2, NEt2, OBut; R=Me, Et, Ph) were smoothly prepared from the corresponding α-(methyl-p-tolyl)hydrazonylated ketones, amides and esters via [2+2] cycloaddition with phenoxyketene. The reaction was generally high-yielding and diastereoselective, leading to β-lactams with a cis relationship between the PhO and the COX moieties, except for R=Ph, where an opposite stereoselectivity was instead observed. The azetidinones represent interesting intermediates which couple protection at N(1) and functionalization at position 4 of the ring. Deprotection of N(1) can be easily attained by oxidative N-N cleavage with magnesium monoperoxyphthalate. 相似文献
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Pyrazole, thiazolidinone, and azetidinone derivatives were synthesized from chalcones of 4-hydroxycoumarin. The structures of all the synthesized compounds were confirmed on the basis of spectral and analytical data. The compounds were screened in vitro for their antibacterial activity against various bacterial strains. 相似文献
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Marcel Gielen Hassan Dalil Monique Biesemans Bernard Mahieu Dick de Vos Rudolph Willem 《应用有机金属化学》1999,13(7):515-520
Di‐n‐butyl‐, triphenyl and tri‐n‐butyltin derivatives of 3 S, 4 S ‐3‐[( R )‐1‐(tert‐butyldimethyl‐<?tw=103.5%>silyloxy)ethyl‐4‐[( R )‐1‐carboxyethyl]‐2‐azetidi<?tw>‐none were synthesized and characterized. Their antitumour activity was screened against seven tumoural cell lines of human origin. Copyright © 1999 John Wiley & Sons, Ltd. 相似文献
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In the presence of Zn/Cp2TiCl2 (cat.) α-bromoacetates, γ-bromocrotonates or α-bromomethylacrylates react with imines in one-pot to form β-lactams, 3-vinyl-β-lactams or α-methylene-γ-lactams, respectively, at room temperature without the need for pretreatment of the solvent and Zn. 相似文献
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Exposure of 3α-chloro-3-phenylthioazetidin-2-ones and allyltrimethylsilane to a Lewis acid promotes a remarkably facile and stereoselective C-3 allylation to give 3α-allyl-3-phenylthioazetidin-2-ones 4 in excellent yield. These allylated azetidin-2-ones undergo smooth desulphurization with tri-n-butyltin hydride or Raney-nickel producing cis-3-allyl- and cis-3-propylazetidin-2-ones. 相似文献
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Christophe Jacopin Mathieu Laurent Marc Belmans Luc Kemps Marcel Crsiat Jacqueline Marchand-Brynaert 《Tetrahedron》2001,57(52):10383-10389
5-{3-[1-(tert-Butyldimethylsilyloxy)ethyl]-4-oxo-azetidin-2-yl}-2,2,5-trimethyl-[1,3]dioxane-4,6-dione (3) has been submitted to nucleophilic attack with various nucleophiles. Meldrum's moiety transesterification, C4-substitution, β-lactam ring opening and Meldrum's moiety decarboxylation were observed. Reaction of 3 with ethanethiol and dimethylaminopyridine in ethanol quantitatively furnished ethyl 2-{3-[1-(tert-butyldimethylsilyloxy)ethyl]-4-oxo-azetidin-2-yl}-thiopropionate as the 1:1 mixture of β (7a) and (8a) diastereoisomers. 相似文献
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