153923-34-3Relevant articles and documents
Base-induced solvolyses of [3.2.1]bicyclic α,α′-dichloro ketones - 1,3-transposition and ring-contraction
Foehlisch, Baldur,Radl, Andreas,Schwetzler-Raschke, Ruediger,Henkel, Sonja
, p. 4357 - 4365 (2007/10/03)
2,4-Dichlorobicyclo[3.2.1]oct-6-en-3-one (1) and its spirocyclopropane (4) and 8-oxa analogues (15, 16) react with methanolic sodium methoxide to furnish bicyclic α-oxo-acetals (3b, 5b, 17, 18) through an enolization/ionization mechanism. With trifluoroethanol/sodium trifluoroethoxide, the corresponding trifluoroethyl acetals (3a and 5a) are formed. Basic hydrolysis affords 2-endo-hydroxynorbornene-2-exo-carboxylic acid (20x) and the 7-oxa analogues (22x, 23x), presumably through benzilic acid rearrangement of the α-diketones.
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.
Enantiomerically Pure Chiral Building Blocks for Syntheses of Carbocyclic Nucleoside Analogues: A Formal Synthesis of Aristeromycin
Helmchen, Guenter,Krotz, Achim,Neumann, Hans-Peter,Ziegler, Manfred L.
, p. 1313 - 1318 (2007/10/02)
(+)-(1R,4R)-Bicyclohept-5-en-2-one (7) was prepared in 78.5percent yield by oxidative degradation of (+)-(1R)-endo-bicyclohept-5-ene-2-carboxylic acid (4) by using an improved procedure for the oxidation of the dianion of 4 with dioxygen.Dihydroxylation of 7 with osmium tetroxide furnished the cis exo addition product 8c and, via reversible retro aldol reaction, the trans isomer 8t which was characterized by X-ray crystal structure analysis. 8c was transformed in four reaction steps into the lactone 2 which is a known starting material for a synthesis of the antiviral antibiotic aristeromycin (1). 8t is a potential starting material for syntheses of carbocyclic analogues of arabinofuranosyl nucleotides, e.g., the antiviral agent cyclaradine (3). - Key Words: Antiviral agents/ Aristeromycin/ Cyclaradine/ (+)-(1R,4R)-5-Norbornen-2-one/ 2-Norbornanones, 5,6-dihydroxy-
Unsaturated acid derivatives in Diels-Alder cycloadditions: Effect of the extended or cross conjugation
Branchadell,Oliva,Ortuno,Rafel,Ventura
, p. 9001 - 9012 (2007/10/02)
Beahvior of pentadienoic acid derivatives in Diels-Alder cycloadditions has been examined in the light of experimental results and theoretical calculations. The effect of cross conjugation to an electron-releasing group has also been investigated for these systems and for simple acrylic acid derivatives.
ASYMMETRIC SYNTHESIS. PREPARATION OF CHIRAL METHYL CHIRAL LACTIC ACID BY CATALYTIC ASYMMETRIC HYDROGENATION.
Fryzuk,Bosnich
, p. 3043 - 3049 (2007/10/11)
In the reported experiments, chiral methyl chiral lactic acid, a molecule which has a chiral methyl group because of the specific incorporation of the three isotopes of hydrogen, has been synthesized by a sequence of simple, convenient steps culminating in catalytic asymmetric hydrogenation. Moreover, the method allows for the preparation of all twelve possible isomers which arise from the permutation of the isotopes of hydrogen and of the two chiral centers. The absolute configuration of the chiral methyl group has been established. Chiral methyl chiral lactic acid is potentially a key molecule for biogenesis studies because numerous other specifically labeled substrates can be prepared from it by simple elaboration and degradation.
