Results 151 to 160 of about 3,980 (188)
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Synthesis and X‐Ray Study of Novel Azofurazan‐Annulated Macrocyclic Lactams.
ChemInform, 2005AbstractFor Abstract see ChemInform Abstract in Full Text.
Aleksei B. Sheremetev +4 more
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Macrocyclic Lactam Synthesis via a Ring Expansion Reaction: Construction of the Cripowellin Skeleton
Organic Letters, 2005[reaction: see text] The cripowellin ring skeleton, a macrocyclic [2.3.5]-bicyclic ketolactam, was smoothly generated via construction of a spiro(benzazepin-cyclohexane-1,3-dione) employing oxidative cyclization as a key step and a subsequent ring expansion reaction.
Bongjin, Moon +3 more
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2009
Conformationally controlled alkylations of lactams 65, 66, 67 and 68 were investigated. High stereoselectivity was obtained in the alkylation of the dianion of lactams 65, 66 and 67. The alkylation of 65 gave products 92 and 93 in a >99:1 ratio. Alkylation of 66 gave 94 and 95 in a 62:1 ratio, and alkylation of 67 gave 96 and 97 in a 10:1 ratio. The
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Conformationally controlled alkylations of lactams 65, 66, 67 and 68 were investigated. High stereoselectivity was obtained in the alkylation of the dianion of lactams 65, 66 and 67. The alkylation of 65 gave products 92 and 93 in a >99:1 ratio. Alkylation of 66 gave 94 and 95 in a 62:1 ratio, and alkylation of 67 gave 96 and 97 in a 10:1 ratio. The
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Calcium complexes of macrocyclic lactams: their structure and calcium induced conformational changes
Journal of the Chemical Society, Perkin Transactions 2, 2000We have examined the coordination sites of calcium complexes of macrocyclic bislactams and found that macrocyclic lactams are able to form solid complexes with Ca2+ ions located inside or outside the cavity depending on the ring’s size. The X-ray structures for the complex [Ca(1)(H2O)4](ClO4)2 (1–Ca2+2+2+) with 20-membered bisamide 1, where a calcium ...
Agnieszka Szumna +2 more
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Ring expansion reactions in the formation of macrocyclic lactams. A synthesis of desoxo-inandenine
Tetrahedron Letters, 1984Abstract Desoxo-inandenine, a reduction product of the macrocyclic spermidine alkaloids inandenin-12-one and-13-one has been synthesized starting from 2-nitro-cyclotridecanone by ring expansion reactions including a Zip reaction step.
Rudolf Wälchli +2 more
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Samarium diiodide induced ring enlargement of azidocyclododecanones to various macrocyclic lactams
Tetrahedron, 1995Abstract The synthesis of 2-cyanocyclododecanones 3 a-c α-substituted by an azidoalkyl chain is described. Compounds 3a (n=3) and 3b (n=4) were treated with SmI2 to afford in one step, the macrocyclic lactams 4a and 4b via five- and six- membered rings, respectively.
Catherine Goulaouic-Dubois +2 more
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Synthesis of Vaniprevir (MK-7009): Lactamization To Prepare a 22-Membered Macrocycle
The Journal of Organic Chemistry, 2011Development of a practical synthesis of MK-7009, a 22-membered macrocycle, is described. A variety of ring-closing strategies were evaluated, including ring-closing metathesis, intermolecular palladium-catalyzed cross-couplings, and macrolactamization.
Zhiguo J. Song +17 more
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β-Lactams as building blocks in the synthesis of macrocyclic spermine and spermidine alkaloids
Tetrahedron, 2002Abstract Syntheses of the macrocyclic spermidine alkaloids (±)-celacinnine ( 1 ) and (±)-dihydroperiphylline ( 2 ) as well as the related spermine alkaloid (±)-verbascenine ( 3 ) were accomplished by means of sequential ring expansions of smaller lactam rings.
Harry H Wasserman +2 more
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Synthesis and antimicrobial evaluation of novel bis-β-lactam grafted macrocycles.
Medicinal chemistry (Shariqah (United Arab Emirates)), 2015A series of macrocyclic bis-β-lactams has been synthesized in three good yielding steps using a Staudinger [2+2] cycloaddition reaction of ketene derived from phenoxyacetyl chloride as the key step. The reaction provided a diastereomeric mixture of cis-anti-cis (C2-symmetry) and cis-syn-cis (meso) bis-β-lactam grafted macrocycles which were screened ...
Natarajan, Arumugam +5 more
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Effect of macrocyclic lactam receptors on extraction of heavy metals and chromate anions
Journal of Inclusion Phenomena and Macrocyclic Chemistry, 2010The article presents the syntheses and extraction properties of new lactam ionophores. These lactam derivatives were easily synthesized via aminolysis of 2,2′-methylenebis(4-chlorophenol) dimethylester with corresponding diamine compounds in methanol–dichloromethane solvent systems at one step, respectively.
Ertul, Seref, Azak, Hacer
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