25435-53-4Relevant academic research and scientific papers
Enantioselective syntheses of diquinane and (cis, anti, cis)-linear triquinanes
Srikrishna,Gowri, Vijayendran,Neetu, Ghodke
scheme or table, p. 202 - 207 (2010/05/02)
The enantioselective syntheses of diquinane and cis, anti, cis-linear triquinanes, starting from the readily available (S)-campholenaldehyde, employing an intramolecular rhodium carbenoid CH insertion reaction, are described.
Efficient rearrangement of epoxides catalyzed by a mixed-valent iron trifluoroacetate [Fe3O(O2CCF3)6(H2O)3]
Ertürk, Erkan,G?llü, Mehmet,Demir, Ayhan S.
experimental part, p. 2373 - 2377 (2010/06/16)
The mixed-valent oxo-centered triiron(III, III, II) trifluoroacetate complex [Fe2IIIFeIIO(O2CCF3)6(H2O)3] was prepared by reacting anhydrous iron(III) chloride with boiling trifluoroacetic acid under nitrogen. The non-hygroscopic and readily available mixed-valent triiron trifluoroacetate complex was found to be an efficient catalyst for the regioselective rearrangement of epoxides. A number of carbonyl compounds formed via the rearrangement of epoxides could be obtained by a simple filtration of the reaction mixture through a short plug of silica gel.
Scope and mechanism of intramolecular aziridination of cyclopent-3-enyl- methylamines to 1-azatricyclo[2.2.1.02,6]heptanes with lead tetraacetate
Hu, Huayou,Faraldos, Juan A.,Coates, Robert M.
supporting information; experimental part, p. 11998 - 12006 (2009/12/08)
A series of seven cyclopent-3-en-1-ylmethylamines bearing one, two, or three methyl substituents at the C2, C3, C4, or Cα positions, including the unsubstituted parent, was accessed by ring-closing metatheses of α,α-diallylacetonitrile (or methallyl variants) and α,α-diallylacetone followed by hydride reductions or reductive amination, or by Curtius degradations of α,α-dimethyl- and 2,2,3-trimethylcyclopent-3-enylacetic acids. Oxidation of the primary amines with Pb(OAc)4 in CH2Cl2, CHCl3 or benzene in the presence of K2CO3 effected efficient intramolecular aziridinations, in all cases except the α-methyl analogue (16), to form the corresponding 1-azatricyclo[2.2.1.02,6]heptanes, including the novel monoterpene analogues, 1-azatricyclene and the 2-azatricyclene enantiomers. The cumulative rate increases of aziridination reactions observed by 1H NMR spectroscopy in CDCl3 resulting from the presence of one or two methyl groups on the cyclopentene double bond, in comparison to the rate of the unsubstituted parent amine (1:17.5:>280), indicate a highly electrophilic intermediate as the nitrene donor and a symmetrical aziridine-like transition state. A mechanism is outlined in which the amine displaces an acetate ligand from Pb(OAc)4 to form a lead(IV) amide intermediate RNHPb(OAc)3 proposed as the actual aziridinating species.
Synthetic approaches to neorogiolanes: enantiospecific synthesis of 12-methoxyneorogiola-1,3,5,7(17),8-pentaene
Srikrishna, Adusumilli,Gowri, Vijayendran
, p. 1663 - 1666 (2008/02/10)
Enantiospecific synthesis of 12-methoxyneorogiola-1,3,5,7(17),8-pentaene, containing the complete carbon framework of the natural diquinane diterpenes neorogioldiols, starting from (S)-campholenaldehyde is described.
Chiral synthons from α-pinene: enantioselective syntheses of bicyclo[3.3.0] and [3.2.1]octanones
Srikrishna, Adusumilli,Beeraiah,Satyanarayana, Gedo
, p. 1544 - 1548 (2007/10/03)
Enantioselective syntheses of bicyclo[3.3.0]octan-3-one, bicyclo[3.2.1]octan-3-one and bicyclo[3.2.1]octan-2-one derivatives were accomplished by employing a chiron based approach, using intramolecular rhodium carbenoid C-H insertion, acid catalysed cyclisation of α-diazo ketone and intramolecular type II carbonyl ene reactions as key steps.
Thermal isomerization of isoborneols and dehydroisoborneols to new chiral building blocks in terpenoid synthesis
Rueedi, Georg,Hansen, Hans-Juergen
, p. 1968 - 1989 (2007/10/03)
The substituted isoborneols 1a-1g and 5,6-dehydroisoborneols 6a-6c, readily prepared in excellent yields from (+)-camphor and (+)-5,6-dehydrocamphor (2) by aryl, vinyl, or alkyl Grignard addition in the presence of stoichiometric amounts of CeCl3, were thermally isomerized in a flow reactor system under DGPTI (dynamic gas-phase thermo-isomerization) conditions at temperatures between 480 and 630° to give the enantiomerically pure monocyclic carbonyl compounds 7a-7d, 19a,b, 23, and 24. In all cases, product formation proceeded highly regio- as well as stereoselectively. The absolute configurations of the new stereogenic centers were determined by 1H-NOE measurements. DGPTI of the aryl substrates 1a-1d is proposed to effect initial cleavage of the weakest single bond in the molecule under formation of a diradical intermediate state followed by intramolecular H-abstraction to afford the acetophenone derivatives 7a-7d. This reaction path was further supported by a 2H-labeling study showing the OH group to be the exclusive H-source. In contrast, DGPTI of the vinyl substrates 1e and 6b allowed concerted retro-ene and oxy-Cope rearrangements. In the case of 5,6-dehydro-2-phenylisoborneol (6a), concomitant diradical and retro-Diels-Alder reaction pathways could be observed. In addition, a new route to (+)-rrans-a-campholanic acid (9) and (+)-trans-a-dihydrocampholytic acid (14) is presented by regioselective Baeyer-Villiger oxidation and subsequent hydrolysis of 7c and 7d, respectively.
Ring cleavage of camphor derivatives: formation of chiral synthons for natural products synthesis
Hutchinson, J. H.,Money, T.,Piper, S. E.
, p. 854 - 860 (2007/10/02)
Base-promoted ring cleavage of 9,10- and 8,10-dibromocamphor provides chiral intermediates for natural product synthesis.
Insect Growth Regulators. XIII - Juvenoids with Cyclopentene Ring. Synthesis of Alkyl ω-(2,2,3-Trimethyl-Cyclopent-3-en-1-yl)-2-alkenoates and ω-(2,2,3-Trimethyl-Cyclopent-3-en-1-yl)alkyl Phenyl Ethers
Derdzinski, K.,Wawrzenczyk, C.,Zabza, A.,et al.
, p. 196 - 212 (2007/10/02)
Neue Analoga der Insektenjuvenilhormone mit dem Cyclopentenring wurden aus dem (2,2,3-Trimethyl-cyclopent-3-en-1-yl)acetonitril (1) durch eine mehrstufige Synthese erhalten.Die Ether 7a-c, 8a, b, 15a-c und 34a, b wurden durch Alkylierung der 4-substituierten Phenolate mit entsprechenden Tosylaten oder Bromiden synthetisiert.Die Ester 11a-c, 12a, b, 21a-c, 23a-c, 28a, b, 29, 27 und 33a, b mit unterschiedlicher Kettenlaenge wurden durch die Wadsworth-Emmons-Reaktion der Ketone 11, 12, 19, 26, 27, 32 bzw. des Aldehydes 16 mit entsprechenden Phosphonsaeurealkylestern erhalten.
MICROBIOLOGICAL TRANSFORMATIONS-XV; MICROBIOLOGICAL TRANSFORMATIONS OF 1-(2,2,3-TRIMETHYLCYCLOPENT-3-EN-YL)-PROPAN-2-ONE AND THEIR HOMOLOGUES BY ACREMONIUM ROSEUM s.s. GAMS 1971
Siewinski, A.,Dmochowska-Gladysz, J.,Kolek, T.,Zabza, A.,Derdzinski, K.,Nespiak, A.
, p. 2265 - 2270 (2007/10/02)
The microbiological transformations of 1-(2,2,3-trimethylcyclopent-3-en-yl)-propan-2-one (2a) and its four (2b-e) homologues by Acremonium roseum were investigated.For 2a, b and e ketones Baeyer-Villiger oxydation was predominant reaction, but ketone 2c and d were mainly hydroxylated.
Total synthesis of zizaane sesquiterpenes: (-)-khusimone, (+)-zizanoic acid, and (-)-epizizanoic acid
Liu, Hsing-Jang,Chan, Wing Hong
, p. 1081 - 1091 (2007/10/02)
Three sesquiterpenes of the zizaane family, khusimone (1), epizizanoic acid (3), and zizanoic acid (2) have been synthesized in optically active form from the ammonium salt of (-)-l-10-camphorsulfonic acid in sixteen, nineteen, and twenty steps respectively.
