3-Amino-2-cyclohexene-l-one

Enantiocontrol of the photocyclization of Ar-methyl-AT-phenyl-3-amino-2-cyclohexen-l-one (151a,b) to the corresponding AT-methylhexahydro-4-car-bazolones (153a,b) via the dipolar ionic intermediate (152a,b) (Scheme 22) was also accomplished by photoirradiation of 1 1 inclusion complexes of 151 a,b with the chiral hosts lOa-c. Of the complexes prepared, 10a-151a, 10a-151b,... 

Analogously, starting from A-methyl-A-phenyl-3-amino-2-cyclohexen-l-one derivatives, an enantioselective reaction took place forming A-methylhexahy-dro-4-carbazolones.5 ... 

Diaminodiphenyl ether is a synonym for 4,4 -oxydianiline (ODA). These compounds are prepared by refluxing alkali aminophenates with chloronitrobenzene in dimethylformamide. 3,4 -Diaminodiphenyl ether is prepared by dehydrogenating 3-amino-2-cyclohexene-l-one. ... 

The process involves three steps partial hydrogenation of MPD to 3-amino-2-cyclohexene-l-imine (3-ACI), hydrolysis of the imine to 3-amino-2-cyclohexene-1-one (3-ACO), and dehydrogenation of 3-ACO to MAP (scheme 6.37). 

An important contribution elucidating the potential of primary amines derived from Cinchona alkaloids has been the aldol cyclodehydration of achiral 4-substituted-2,6-heptanediones to enantiomerically enriched 5-substituted-3-methyl-2-cyclohexene-l-ones, presented by List and coworkers in 2008 (Scheme 14.26). Both 9-deo>y-9-amino-epr-quinine (QNA) and its pseudoenantiomeric, quinidine-derived amine QDA, in combination with acetic acid as cocatalyst, proved to be efficient and highly enantio-selective catalysts for this transformation, giving both enantiomers of 5-substituted-3-methyl-2-cyclohexene-l-ones with very good results. The authors observed that proline and the catalytic antibody 38C2 delivered poor enantioselectivity in this reaction. Furthermore, the synthetic utility of the reaction was exemplified by the first asymmetric synthesis of both... 

Finally, a quinine-derived primary amine was successfully applied by List et al. to catalyse the intramolecular aldolisation of 4-substituted-2,6-heptanediones to highly valuable synthetic targets, chiral 5-substituted-3-methyl-2-cyclohexene-l-ones, which has been a long-term challenge in asymmetric catalysis. Therefore, these reactions performed in the presence of 9-amino-9-deoxyepiquinine combined with acetic acid as an additive afforded the desired products with excellent yields and enantioselectivities, as shown in Scheme 2.40. 

Obtained by aromatization of 4,6-diacetyl-5-[4-(dimethyl-amino)phenyl]-3-methyl-2-cyclohexen-l-one (m.p. 117°) with bromine in chloroform (45%) or by heating at 170° for 3 h [5832]. 

Chiral Ligand of LiAlH4 for the Enantioselective Reduction of a,p-Unsaturated Ketones. Enantioselective reductions of a,p-unsaturated ketones afford optically active ally lie alcohols which are useful intermediates in natural product synthesis. Enantioselective reduction of a,p-unsaturated ketones with LiAlH4 modified with chiral amino alcohol (1) affords optically active (S)-allylic alcohols with high ee s. When 2-cyclohexen-l-one is employed, (5)-2-cyclohexen-l-ol with 100% ee is obtained in 95% yield (eq 2). This is comparable with the results obtained using LiAlH4-chiral binaphthol and chiral 1,3,2-oxazaborolidine. ... 

Benzoyl-l-phenyl-5-methoxycarbonyl-2,3-dihydro-pyrrole-2,3-dione was reacted with 5/5-dimethyl-3-p-methoxyphenylamino-2-cyclohexen-l-one in boiling benzene to afford 6,6-d imethyl-1 -p-methoxyphenyl-2,4-dioxo-2,3,4,5,6,7-hexahydro-lH-indole-3-spiro-2-(3-benzoyl-5-oxo-4-phenyl-amino-2,5-dihydrofuran) in high yield. The reaction proceeded by the enamine addition to the 2-carbonyl group with ring opening, followed by double cyclization (06RJOC772). 

Benzaldehyde and a little acetic acid added to an ethanolic soln. of 3-(o-amino-anilino)-5,5-dimethyl-2-cyclohexen-l-one, and allowed to stand 1 hr. at room temp. 3,3-dimethyl-2,3,4,5,10,ll-hexahydro-ll-phenyl-lH-dibenzo[b,e][l,4]di-azepin-l-one. Y 94.3%. F. e, s. S. Miyano and N. Abe, Chem. Pharm. Bull. 20, 1588 (1972). 

Ukhin LY, Suponitsky KY, Shepelenko EN, Belousova LV, Borodkin GS (2012) Novel synthesis of oxonine derivatives from 3-[(2-aminophenyl)amino]-5,5-dimethyl-2-cyclohexene-l-one and o-quinones. Tetrahedron Lett 53(l) 67-70. doi 10.1016/j.tetlet.2011.10.147 Vachon J, Harthong S, Dubessy B, Dutasta JP, Vanthuyne N, Roussel C, Naubron JV (2010) The absolute configuration of an inherendy chiral phosphonatocavitand and its use toward the enantioselective recognition of L-adrenaline. Tetrahedron Asymm 21(11-12) 1534—1541. doi 10.1016/j.tetasy.2010.03.028... 

Cyclocondensation of cis- and trans-2-amino-4-cyclohexene-l-carboxylic acid with 2-methoxy-3,4,5,6-tetrahydropyrimidine in boiling chlorobenzene for 6 h gave ds-4a,lla-H- and trani-4a,lla-H-l,4,4a,6,7,8,9,lla-octahydro-1 l//-pyrido[2,l-6]quinazolin-l 1-ones (75 and 78) (90PHA109). 

Chemical reduction [with aqueous titanium(III) chloride in dilute acetic acid] or catalytic reduction (in the presence of 10% palladium-on-charcoal by transfer hydrogenation from cyclohexene or with hydrogen) of 3-nitro-4//-pyrido[l,2-a]pyrimidin-4-ones 176 (R = H, 8-Me, 8-OMe, 7-C1) gave 3-amino-4//-pyrido[l,2-a]pyrimidin-4-ones [90JCR(S)308]. Chemical and catalytic reduction of 3,8-dinitro-9-hydroxy-4//-pyrido[l,2-a]pyrimidin-4-one yielded an unstable product. 

Dihydro-2-isopropyl-3.6-dimethoxypyrazine, a bis(lactim)ether, is converted into the 5-di-azo compound 1 by lithiation and diazo group transfer. The intermediate diazo compound reacts at room temperature with olefins such as cyclohexene to produce the cyclopropane derivatives with excellent diastereoselectivity . The derivative from cyclohexene is hydrolyzed by acid treatment to give methyl 7-cv(cfo-aminobicyclo[4.1.0]hcptane-7-carboxylate. The bis(lac-tim)ether diazo compound 1 is also involved in an exceptional asymmetric [2 + 1J cycloaddition producing cnantiomerically pure cyclopropenc derivatives4. Thus, reactions of the diazo compound with monosubstituted alkynes afford the spiro compounds as one diastereomer. Hydrolytic removal of the auxiliary and protection of the amino group provides enantiomerically pure methyl l-amino-2-arylcyclopropene-l-carboxylates in moderate overall yield. 

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