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3-Ethoxycarbonyl-47/-pyran, reactions

N-Methyl-4-hydroxy-2-quinolone 183 in a three-component reaction gives spiro pyrano[3,2-c]qionoline-2-ones (02MI2), but indolones 213 with 4-hydroxy-6-methyl-2-pyridone 177 react in a complicated way (97BCJ1625). Ethoxycarbonyl-methylene indolone (Z = COOEt) forms pyrans 224, while dicyano analogs (Z = CN) yield substituted quinoline 225 (Scheme 85). [Pg.225]

A hetero-Diels-Alder reaction has been used to prepare racemic 2-ethoxycarbonyl-3,6-dihydro-2H-pyran (9). This ester 9 was resolved by Bacillus lentus protease to provide the R-isomer. Reduction, protection, and ozonolysis provided the bis-mesylate 10 (Scheme 26.9), a key intermediate in the synthesis of the PKC (protein kinase C) inhibitor LY333531 (ll).278 This resolution approach was used because it was more efficient than an asymmetric Diels-Alder reaction. [Pg.513]

Isobutoxy-217, 2-butyl-,218 2-phenyl- (eq. 12.113),218 and 2-ethoxycarbonyl-219 substituted 2,3-dihydro-4H-pyrans were hydrogenated over Raney Ni at room temperature and elevated hydrogen pressures, although rather long reaction times were required for the 2-isobutoxy and 2-phenyl derivatives. [Pg.555]

A cost effective and easily scaled-up process has been developed for the synthesis of (S)-3-[2- (methylsulfonyl)oxy ethoxy]-4-(triphenylmethoxy)-1 -butanol methanesulfonate, a key intermediate used in the synthesis of a protein kinase C inhibitor drug through a combination of hetero-Diels-Alder and biocatalytic reactions. The Diels-Alder reaction between ethyl glyoxylate and butadiene was used to make racemic 2-ethoxycarbonyl-3,6-dihydro-2H-pyran. Treatment of the racemic ester with Bacillus lentus protease resulted in the selective hydrolysis of the (R)-enantiomer and yielded (S)-2-ethoxycarbonyl-3,6-dihydro-2H-pyran in excellent optical purity, which was reduced to (S)-3,6-dihydro-2H-pyran-2-yl methanol. Tritylation of this alcohol, followed by reductive ozonolysis and mesylation afforded the product in 10-15% overall yield with excellent optical and chemical purity. Details of the process development work done on each step are given. [Pg.349]

To a 20 mL flask was added 2.5 g of (R,S)-2-ethoxycarbonyl-3,6-dihydro-2H-pyran, followed by 7 mL of 0.2 M pH 7.5 phosphate buffer and 2 mL of Bacillus lentus protease-III solution (approximately 5% solution of the protein). The biphasic solution was stirred at room temperature (23 °C) using a magnetic stirrer. The pH was checked at 0.5 hour intervals and readjusted to 7.5 by the drop-wise addition of 1 N NaOH (approximately 7 mL were required over the complete reaction). The progress of the reaction was monitored by chiral gas chromatography. After 5 hours, the enantiomeric purity of the unreacted ester was >99% and the reaction was stopped by the addition of 10 mL of MTBE. The pH of the aqueous phase was adjusted to 8.5 and the mixture was transferred into a separatory funnel. The aqueous phase was extracted twice with 20 mL of MTBE and the combined organic layers were extracted once with saturated sodium bicarbonate (10 mL), followed by saturated sodium chloride solution (10 mL), and the organic... [Pg.359]

The dimethylamino group in diethyl (2 R=Et) and dimethyl 1-dimethylamino-3-oxobut-l-ene-2,4-dicarboxylates (2 R=Me) can be exchanged very easily with nitrogen nucleophiles. With primary amines in methanol or ethanol under reflux for several hours, substitution of the dimethylamino group by an amine takes place followed by intramolecular nucleophilic attack of the amino group on the ester to afford 1-substituted 5-alkoxycarbonyl-4-hydroxypyridin-2(lH)-ones 56 in 16-93% yields (5cheme 21). In the reaction of 56 with methyl (Z)-2-benzoylamino-3-dimethylaminopropenoate (57), first the intermediate 58 was formed, which cyclized into 6-substituted 3-benzoylamino-8-ethoxycarbonyl-2H,5H-pyrido[4,3-li]pyran-2,5-diones (59). However, with 3-dimethyla-mino-2-(methoxycarbonyl)propenoate (60) intermediate 61 is formed... [Pg.161]


See other pages where 3-Ethoxycarbonyl-47/-pyran, reactions is mentioned: [Pg.757]    [Pg.442]    [Pg.244]    [Pg.757]    [Pg.352]    [Pg.360]    [Pg.102]    [Pg.587]    [Pg.125]    [Pg.324]   
See also in sourсe #XX -- [ Pg.62 , Pg.102 ]




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4 -ethoxycarbonyl

Ethoxycarbonylation

Pyran reactions

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