- New chiral cyclopalladated complexes based on the pinane and bornane imines
-
2α-Hydroxypinan-3-one imino derivatives react with lithium tetrachloropalladate to form palladacycles, while similar bornane derivative undergo cyclopalladation only when treated with palladium acetate.
- Kuchin,Gur'eva,Frolova,Alekseev,Zalevskaya
-
p. 745 - 750
(2014/01/23)
-
- Preliminary investigations on novel camphor-derived chiral sulfones: Completely stereoselective formation of tricyclic β-hydroxy sulfones from 8- and 10-functionalized camphor derivatives
-
Some camphor-derived chiral allylic and benzylic sulfones in which the sulfonyl group is located at the C-10, C-9 or C-8 methyl groups of (+)-camphor were synthesized. The C-9 and C-8 substituted sulfones were obtained via Wagner-Meerwein rearrangements of the bicyclic camphor framework. On treatment with LDA, the C-10 and C-8 substituted sulfones cyclized with complete stereoselectivity, affording tricyclic β-hydroxy sulfones whose relative configurations were determined by X-ray crystallography. Tricyclic sulfones 23 and 24 underwent both β-elimination and retro-aldol reactions on further exposure to base. Reduction of the carbonyl group of the C-10 substituted sulfones afforded exo-configured isobornyl sulfones with high stereoselectivity. Reaction of the lithiated isobornyl benzyl sulfone 32 with benzaldehyde generated all four of the possible product diastereomers, of which three were isolated pure by chromatography. Attempted desulfonylation of these diastereomers failed to generate the desired optically active homobenzylic alcohols but the same sulfonyl carbanion trapping/desulfonylation sequence was successful in a model achiral series of compounds.
- Lewis, Frank W.,McCabe, Thomas C.,Grayson, David H.
-
supporting information; experimental part
p. 7517 - 7528
(2011/10/12)
-
- REACTIVITY OF 3-BROMOCAMPHOR AND 3-BROMOISOCAMPHANONE UNDER THE CONDITIONS OF THE RITTER REACTION
-
The bromination of camphor and isocamphanone yield, respectively, 3-endo- and 3-exo-bromo ketones.Under the conditions of the Ritter reaction 3-bromocamphor does not react with nitriles, while 3-isocamphanone is selectively converted into the corresponding N,N'-diacyl-3-bromo-2,2-gem-diamino-5,5,6-trimethylbicycloheptanes.
- Koval'skaya, S. S.,Kozlov, N. G.,Zyryanov, V. A.
-
p. 722 - 726
(2007/10/02)
-
- Synthesis and Absolute Configuration of the Antiparasitic Furanosesquiterpenes (-)-Furodysin and (-)-Furodysinin. Camphor as a Six-Membered Ring Chiral Pool Template
-
The syntheses of (-)-furodysin ((-2)-2a) and (-)-furodysinin ((-)-3a) in four steps starting from (+)-9-bromocamphor (18) has been accomplished, thus establishing the absolute configuration of these and related metabolites.This was made possible by the unexpected exo selectivity in the aldol condensation of camphor-like enolates with aldehydes.This has been found to be a general phenomenon in the camphor system.Further, anionic fragmentation of the C1-C7 bond of camphor derivatives has allowed access to synthetic intermediates containing functionalized six-memberedrings, thus opening up avenues from camphor to a new class of chiral pool elements not currently available from chiral pool substances.
- Vaillancourt, Valerie,Agharahimi, Mohamad R.,Sundram, Uma N.,Richou, Olivier,Faulkner, D. John,Albizati, Kim F.
-
p. 378 - 387
(2007/10/02)
-
- ENANTIOSPECIFIC SYNTHESIS OF ESTRONE
-
Efiicient cleavage of the C(1)-C(2) bond in 9,10-dibromocamphor (3) provides a chiral intermediate (5) that can be used in a new enantiospecific synthesis of estrone.
- Hutchinson, John H.,Money, Thomas
-
-
- The Chemistry of Terpenes. Part 26. A Re-examination of the Neutral Products of the Oxidation of (-)-Fenchone, and (+)-2-endo-Fenchyl Acetate, and of the Bromination of (+)-Fenchone.
-
A re-examination of the products of oxidation of (-)-fenchone (1) with chromyl acetate in acetic acid has confirmed that (-)-fenchane-2,5-dione (2) and (+)-fenchane-2,6-dione (3) are the main products.Two other compounds have been isolated, namely (+)-(1R)-6-exo-acetoxy-3,3,6-trimethyltrinorbornan-2-one (4) and (+)-(1R,2S,6R)-2,8,8-trimethyl-3,5-dioxatricyclo2,6>decane-4,9-dione (5).Similar oxidation of (+)-2-endo-fenchyl acetate (6) yields (-)-(1S)-2-endo-acetoxy-1,3,3-trimethyltrinorbornan-5-one (7), (+)-(1R)-2-endo-acetoxy-1,3,3-trimethyltrinorbornan-6-one (8), (+)-(1S)-2-endo-5-exo-diacetoxy-1,3,3-trimethyltrinorbornane (9), (+)-(1R,5S)-7-endo-acetoxy-1,6,6-trimethyl-3-oxabicyclooctane-2,4-dione (10), and (-)-(1S,3S,7S,8R)-8,10,10-trimethyl-4,6-dioxatricyclo3,8>decane-2,5-dione (11).Derivatives of these compounds are described.Bromination of (+)-fenchone (12) in presence of copper gave (+)-(1R)-1-bromomethyl-3,3-dimethyltrinorbornan-2-one (13) as the major product, but a significant amount of (-)-(1R)-7-anti-bromo-1,3,3-trimethyltrinorbornan-2-one (14) was also formed.Minor amounts of (+)-(1R)-3-endo-bromo-1,7,7-trimethyltrinorbornan-2-one (15), and probably (g.l.c.) either 5-exo- or 6-exo-bromofenchone, were formed.Methanolysis of the anhydride (10) affords the half-ester (16) from which the β-lactone (17) is obtained.
- Cocker, Wesley,Gordon, Robert L.,Shannon, Patrick V. R.
-
p. 2101 - 2147
(2007/10/02)
-
- Correlation of nuclear magnetic resonance spectra and structure of trans-camphane-2,3-diols
-
Evidence is provided to demonstrate that a recent correction in the published nmr spectra of trans-camphane-2,3-diols is unjustified
- Allen, M. S.,Hutchinson, J. H.,Money, T.
-
p. 2707 - 2708
(2007/10/02)
-
- Synthesis of 8,10-and 9,10-disubstituted camphor derivatives
-
Regiospecific bromination and debromination reactions have been used to provide a synthetic route from camphor to optically active 8,10- and 9,10-disubstituted camphor derivatives.
- Dadson, William M.,Lam, Mayda,Money, Thomas,Piper, Susan E.
-
p. 343 - 346
(2007/10/02)
-