90358-31-9

Upstream product

• 674-82-8 4-methyleneoxetan-2-one 
• 65253-04-5 (-)-8-phenylmenthol 
• 5394-63-8 2,2,6-trimethyl-4H-1,3-dioxin-4-one 
• 2033-24-1 cycl-isopropylidene malonate 
• 75-36-5 acetyl chloride 
• 105-45-3 acetoacetic acid methyl ester 
• 141-97-9 ethyl acetoacetate 

Downstream Products

• 1031781-51-7 C₂₀H₂₆N₂O₃ 
• 126421-82-7 (1R,2S,5R)-8-phenylmenthyl 3-acetamidobutanoate 
• 126421-76-9 (1'R,2'S,5'R)-2'-(1-methyl-1-phenylethyl)-5'-methylcyclohexyl (Z)-3-acetamido-2-butenoate 
• 192199-27-2 (R)-2-(4-Chloro-benzyl)-2-methyl-3-oxo-butyric acid (1R,2S,5R)-5-methyl-2-(1-methyl-1-phenyl-ethyl)-cyclohexyl ester 
• 192199-25-0 (R)-2-Benzyl-2-methyl-3-oxo-butyric acid (1R,2S,5R)-5-methyl-2-(1-methyl-1-phenyl-ethyl)-cyclohexyl ester 
• 192199-28-3 (R)-2-Methyl-3-oxo-2-phenethyl-butyric acid (1R,2S,5R)-5-methyl-2-(1-methyl-1-phenyl-ethyl)-cyclohexyl ester 
• 264610-07-3 (E)-2-Chloro-9-(3-isopropyl-2-methoxy-phenyl)-6-methyl-3-oxo-non-6-enoic acid (1R,2S,5R)-5-methyl-2-(1-methyl-1-phenyl-ethyl)-cyclohexyl ester 

Relevant academic research and scientific papers

Mild and high-yielding synthesis of β-keto esters and β-ketoamides

In the presence of sodium acetate, the reaction between 2,2,6-trimethyl-4H-1,3-dioxin-4-one and secondary or tertiary alcohols (including chiral ones) or primary or secondary amines could be carried out in refluxing tetrahydrofuran, under much milder conditions than those described in the literature. In these new conditions, side products normally observed using the traditional protocol were avoided, and-keto esters and-ketoamides were normally obtained in quantitative yields.

Stereoselective formation of a chiral ether by intramolecular O-H insertion reaction of a metal carbenoid generated from diazoacetoacetate

Intermolecular O-H insertion reactions of rhodium carbenoids generated from chiral diazoacetoacetates are less efficient and less stereoselective than the reactions of those generated from the corresponding phenyldiazoacetates. Nevertheless, when the diazoacetoacetate is connected to a phenolic moiety through a 2,4-pentanediol tether, the carbenoid generated shows a high potential in both efficiency and stereoselectivity during the intramolecular O-H insertion reaction to give a cyclic ether in up to 88% diastereomeric excess (de) in quantitative yield. The de value depends on the structure of the tether, but is independent of the catalyst employed. The isomerization of the cyclic ether has been studied under the conditions of equilibrium and kinetic protonation of the corresponding enolate. The similarity between the de values obtained by insertion and those obtained under equilibrium suggests that the rhodium catalyst is eliminated during the early stages of the O-H insertion reaction and that proton transfer, which determines the stereoselectivity, occurs after the elimination of the rhodium metal, independent of the stereochemistry of the initial addition. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.

Asymmetric synthesis of multifunctionalized pyrrolines by a ruthenium porphyrin-catalyzed three-component coupling reaction

(Chemical Equation Presented) Chiral multifunctionalized pyrrolines have been synthesized by a ruthenium porphyrin catalyzed three-component coupling reaction. In a one-pot reaction, ruthenium porphyrins catalyzed in situ generation of chiral azomethine ylides from chiral diazo esters and imines. Asymmetric 1,3-dipolar cycloaddition reactions of the chiral azomethine ylides with dipolarophiles afforded the corresponding pyrrolines in good yields and high diastereoselectivity (up to 92% de).

α,α'-Dioxothiones part 2. Asymmetric Diels-Alder reactions of chiral non-racemic α,α'-dioxothiones

Chiral non-raemic α,α'-dioxothiones 2a-g and 17 are obtained from chiral β-ketoesters using the phthalimidesulfenyl chloride 1 as key reagent. The ability of these thiones to discriminate between the enantiotopic faces of several dienophiles has been evaluated. The best diastereoisomeric excesses (67-80%) were obtained when the a-acyl thiones were involved as electron-poor dienes in inverse electron demand Diels-Alder reactions with electron-rich styrenes as dienophiles. The possibility to obtain thiones bearing two chiral groups as well as the reactions where the a-acyl thiones 2 participate as dienophiles are also shown.

Diastereoselective alkylation of 8-phenylmenthyl 2- methylacetoacetate. Preparation of enantiomerically pure 4,4-disubstituted 2-pyrazolin-5-ones

Alkylation of (1R,3R,4S)-8-phenylmenthyl 2-methylacetoacetate with alkyl halides affords 2-alkyl-2-methylacetoacetates in diastereomeric ratios 72:28 to 85:15. The major R (at C-α) diastereoisomers are converted into enantiopure 4,4-disubstituted 2-pyrazolin-5-ones with recovery of the chiral inductor.

Asymmetric Induction in Mn(III)-Based Oxidative Free-Radical Cyclizations of Phenylmenthyl Acetoacetates and 2,5-Dimethylpyrrolidine Acetoacetamides

Mn(III)-based oxidative free-radical cyclization of phenylmenthyl ester 1e afforded 90percent of 13 with 86percent de.Cyclization of 31b provided 56percent of (+)-podocarpic acid precursor 32e with 82percent de.The direction of de was opposite in these two cases.Oxidative cyclization of α-methyl β-keto ester 44b gave a 1:1.6 mixture of 46b and 47b while α-propyl β-keto ester 44d produced a >10:1 mixture of 46d and 47d indicating that the extent and direction of de is dependent on the size of the α-substituent.The reaction proceeds through transition states 12 and 56 with large α-substituents and through transition states 19 and 57 with small α-substituents.The de depends on the double-bond substitution pattern as shown by the decreased de with 37b and 37d, and selectivity in the 5-exo cyclization of 64b, 65b, 70b, and 71b is low.

Asymmetric syntheses with a new optically active perhydronaphthalene based chiral auxiliary

(1R,4aS,8S,8aS)-8-(5'-Methoxy-2'-methylphenyl)-8-methyldecahydro-1-nap hthalenol 3a is a highly efficient chiral auxiliary in the Diels-Alder addition of its acrylate ester 5 and in the DIBAL-H and Grignard reactions of its phenylglyoxylate ester 7.

New chiral auxiliaries: Their use in the asymmetric hydrogenation of β-acetamidocrotonates

Synthesis of chiral β-amido esters 7 with high diasteroisomeric excess was achieved by asymmetric hydrogenation (H2/PtO2) of stereogenic β-acetamidocrotonates 6 in which the chirality is present in the alkyl of the ester part. For such a purpose, new efficient chiral auxiliaries such as 2,2-diphenylcyclopentanol (12) and 1,1-diphenyl-3-methyl-2-butanol (13) were developed.

NADH Model Reaction: Asymmetric Reduction of Nonactivated Carbonyl Compounds with N-Anionized Hantzsch Ester

As model compounds for NADH coenzymes, three chiral Hantzsch ester-type dihydropyridines were prepared.By their use and 2,6-dimethyl-3,5-dicarbo-(-)-menthoxy-1,4-dihydropyridine that had already been prepared, asymmetric reductions of unactivated prochiral ketones were conducted under the action of alkali metal derivatives at room temperature in a nonpolar solvent, and the alcohol product were obtained in a 36-80percent chemical yield and 30-60percent enantiomeric excess.