2275-26-5Relevant articles and documents
Rearrangements of α-Diazo-β-hydroxyketones for the Synthesis of Bicyclo[m.n.1]alkanones
Li, Zhengning,Lam, Shuk Mei,Ip, Ignatius,Wong, Wing-Tak,Chiu, Pauline
supporting information, p. 4464 - 4467 (2017/09/11)
Rhodium-catalyzed decomposition of fused bicyclic α-diazo-β-hydroxyketones results in good yields of bridged bicyclo[m.n.1]ketones via a rearrangement pathway.
Facile Synthesis of Spirocyclic Lactams from β-Keto Carboxylic Acids
Yang, Wei,Sun, Xianyu,Yu, Wenbo,Rai, Rachita,Deschamps, Jeffrey R.,Mitchell, Lauren A.,Jiang, Chao,Mackerell, Alexander D.,Xue, Fengtian
supporting information, p. 3070 - 3073 (2015/06/30)
A facile synthesis of spirocyclic lactams starting from β-keto carboxylic acids via a one-pot cascade reaction involving a Curtius rearrangement and an intramolecular nucleophilic addition of the enol carbon to the isocyanate intermediate is reported. The same conditions have also been used for the generation of fused cyclic lactams with similar good yields. The synthetic value of this method has been demonstrated by efficient synthesis of tetracyclic spirolactam 8 and pentacyclic spirolactam 9.
Construction of fused cyclooctanoid ring systems via seven-membered ring carbonyl ylides
Muthusamy, Sengodagounder,Babu, Srinivasarao Arulananda,Gunanathan, Chidambaram,Suresh, Eringathodi,Dastidar, Parthasarathi
, p. 801 - 811 (2007/10/03)
A series of α-diazo carbonyl compounds tethered to cyclopentanone/cyclohexanone/1-tetralone units have been synthesized using a diazomethane solution to construct various fused cyclooctane ring systems via rhodium-generated carbonyl ylides. The reaction of rhodium(II) acetate dimer with various α-diazo carbonyl compounds generated transient cyclic seven-membered ring carbonyl ylides, which underwent facile 1,3-dipolar cycloadditions with dipolarophiles, like N-phenylmaleimide, p-benzoquinone, and DMAD to furnish a variety of fused epoxy-bridged cyclooctane ring systems in a tandem manner. Interestingly, an oxepine ring system was generated via an intramolecular proton transfer of a seven-membered ring carbonyl ylide. A tri-oxa polycyclic compound was obtained in the case of p-benzoquinone as dipolarophile. A single-crystal X-ray analysis of a fused cyclootanoid derivative is reported to decisively establish the structure and stereochemistry of the fused epoxy-bridged cyclooctane ring systems; a further analysis revealed the existence of a unique intermolecular C-H ···π interaction motif in the solid-state architecture.
Synthesis of enantiomerically pure bicyclic condensed δ-lactones via microbial reduction and enzymic resolution strategies
Fogal, Erica,Forzato, Cristina,Nitti, Patrizia,Pitacco, Giuliana,Valentin, Ennio
, p. 2599 - 2614 (2007/10/03)
The formation of enantiopure δ-lactones condensed with alicyclic rings has been achieved either by reduction with baker's yeast of the corresponding δ-keto esters and δ-keto acids or by enzymic resolution of the former compounds. The absolute configuratio
Ring-D aromatic phytosteroids; a model for biogenesis by way of carbon radical rearrangement
Green, Stuart P.,Whiting, Donald A.
, p. 1027 - 1034 (2007/10/03)
A mechanism is postulated for the biogenesis of the unique ring-D aromatic phytosteroids from Nicandra physaloides, which involves rearrangement, ring expansion, and aromatisation of a carbon radical generated by cytochrome P450 (Scheme 1). In support, model hydrindene acids 15b and 18b have been synthesized and subjected to homolytic decarboxylation; the latter acid yielded 6-methyltetralin 24, in biomimetic fashion. The isomeric acid afforded not only 6-methyltetralin 24 but also 5-methyltetralin 26; mechanisms for this unusual rearrangement are discussed.
Stereoselective Hydrolysis of Nitriles and Amides Under Mild Conditions Using a Whole Cell Catalyst
Beard, Timothy,Cohen, Mark A.,Parratt, Julian S.,Turner, Nicholas J.,Crosby, John,Moilliet, Jock
, p. 1085 - 1104 (2007/10/02)
An immobilised whole cell Rhodococcus sp. (SP 361) has been shown to be an effective catalyst for the stereoselective hydrolysis of both racemic and prochiral nitrile containing compounds. 2-Alkyl-arylacetonitriles 6a-8a were hydrolysed to (S)-acids and (R)-amides whereas the closely related substrate 9a gave the (R)-acid.A series of prochiral dinitriles 10a-13a were hydrolysed to the corresponding (S)-acids with e.e.'s 22-84percent.Models to account for the stereoselectivity of the enzymic hydrolyses have been proposed.
Stereoselective Synthesis of (cis-Hydrindane) Models for C-18 Radical Reactivity in Steroid C/D Rings
Green, Stuart P.,Whiting, Donald A.
, p. 1753 - 1754 (2007/10/02)
The keto-acid 5 undergoes stereospecific Peterson reaction to afford the (Z)-α-unsaturated ester-acid 6, and the derived phenyl selenoester cyclises also stereospecifically to the cis-hydrindanone 8 via a 5-exo acyl radical process; the ketone 8 is transformed through enone 11 into the diene-acids 2 and 3, models for study of C-18 radical reactions in steroid C/D systems.
Process for the manufacture of 5-oxoalkanoic acids
-
, (2008/06/13)
5-Oxoalkanoic acids are prepared by addition of a ketone containing at least one hydrogen atom in the α-position with regard to the keto group, to an α,β-unsaturated acid. As catalysts secondary amines are present.
