41248-20-8Relevant academic research and scientific papers
Process for producing optically active 2-norbornanone
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, (2008/06/13)
An optically active 5-methylenedioxolan-4-one derivative is subjected to Diels-Alder reaction with cyclopentadiene, and the resulting Diels-Alder reaction product is hydrolyzed to convert it into an optically active 2-hydroxynorbornene-2-carboxylic acid, which is then subjected to catalytic hydrogenation to form an optically active 2-hydroxynorbornane-2-carboxylic acid. The hydroxycarboxylic acid is subjected to oxidative decarboxylation to obtain an optically active 2-norbornanone.
Method for producing optically active 3-substituted-2-norbornanones and their intermediates
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, (2008/06/13)
The present invention provides a method for producing optically active 3-substituted-2-norbornanones which are useful as starting materials for several kinds of physiologically active materials, and to their intermediates, optically active 2-hydroxy-2-norbornanecarboxylic acid and to a method for producing these intermediates.
Total Syntheses of Sandalwood Fragrances: (Z)- and (E)-β-Santalol and Their Enantiomers, ent-β-Santalene
Krotz, Achim,Helmchen, Guenter
, p. 537 - 540 (2007/10/02)
Via asymmetric Diels-Alder reactions, large scale preparations of enantiomerically pure norbornane-2-carboxylic acids were carried out.Oxidative degradation furnished 2-norbornanone and 3-methyl-2-norbornanone which gave the title compounds via stereoselective alkylations, subsequent Wittig reactions and reductions.
Carbon Participation in the Solvolysis of 6-exo-substituted 2-exo- and 2-endo-Norbornyl p-Toluenesulfonates. Norbornanes Part 5
Fischer, Walter,Grob, Cyril A.,Hanreich, Reinhard,Sprecher, Georg von,Waldner, Adrian
, p. 2298 - 2311 (2007/10/02)
The solvolysis rates and products of the 6-exo-substituted 2-exo- 1a-1u, and 2-endo-norbornyl p-toluenesulfonates 2a-2u, have been determined.In general, the rate constants for 1 and 2 (log k) correlate well with the inductive constants ?qI of the substituents at C(6); however, their sensitivity to ?qI is much larger in the 2-exo-series 1 than in the 2-endo-series 2.This differential transmission of polar effects is the cause of decreasing 2-exo/2-endo rate ratios from 2388 for R=t-C4H9 to 0.37 for R=Br, i.e., with increasing electron attraction by the substituent.The high sensitivity of the rate constants for the 2-exo-p-toluenesulfonates 1 to ?qI indicates an unusually strong inductive interaction between C(6) and the incipient cationic center at C(2).This interaction is ascribed to the participation of the pentacoordinate C(6)-atom, i.e. to 1,3-bridging, a consequence of steric hindrance of nucleophilic solvent participation in norbornanes.Donor substituents enhanche 1,3-bridging, lead to faster reactions and to the formation of 2-exo substitution products.Conversely, acceptor substituents reduce 1,3-bridging, decrease rates and facilitate the formation of 2-endo substitution products.Graded 1,3-bridging is discussed in the light of Winstein's nonclassical ion concept.
2-Amino-5-spiro substituted oxazoline-4-one compounds
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, (2008/06/13)
A novel series of 2-amino-5-spiro substituted oxazolin-4-ones and intermediates for making said compounds. These compounds are prepared by first converting the appropriately substituted cycloketone to the corresponding cyclocyanohydrin; converting this co
