- Synthesis method of cis5-tert-butyl-3A-methyl-tetrahydro 1H-furan[3,4 c] pyrrole 3A,5(3H) dicarboxylic ester
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The invention relates to a synthesis method of cis5-tert-butyl-3A-methyl-tetrahydro 1H-furan[3,4 c] pyrrole 3A,5(3H) dicarboxylic ester. The method mainly solves the technical problem that no proper industrial synthesis method exists in the prior art. The method comprises five steps that: 1, a compound 1 uses sodium borohydride as a reducing agent to react in an ethanol solvent to obtain a compound 2; 2, the compound 2 uses tetrahydrofuran as a solvent to obtain a compound 3 under the effects of triphenylphosphine and diisopropyl azodicarboxylate; 3, the compound 3 and the N-methoxymethyl-N-(trimethylsilyl) benzylamine use dichloromethane as a solvent to obtain a compound 4 through room temperature reduction under the action of trifluoroacetic acid; 4, the compound 4 and thionyl chloride react under the methanol backflow condition to obtain a compound 5; 5, the compound 5 uses palladium hydroxide catalysts and Boc anhydride auxiliary agents to obtain a final compound 6 through catalytic hydrogenation reaction.
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- Iridium-catalyzed enantioselective hydrogenation of unsaturated heterocyclic acids
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Spiral binding: A highly enantioselective hydrogenation of unsaturated heterocyclic acids has been developed by using chiral iridium/spirophosphino oxazoline catalysts (see scheme; BArF-=tetrakis[3,5- bis(trifluoromethyl)phenyl]borate, Boc=tert-butoxycarbonyl). This reaction provided an efficient method for the preparation of optically active heterocyclic acids with excellent enantioselectivities. Copyright
- Song, Song,Zhu, Shou-Fei,Pu, Liu-Yang,Zhou, Qi-Lin
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supporting information
p. 6072 - 6075
(2013/07/05)
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- MELANOCORTIN RECEPTOR AGONISTS
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The present invention relates to a compound of the following formula 1, pharmaceutically acceptable salt and isomer thereof effective as agonist of melanocortin receptor, and an agonistic composition of melanocortin receptor comprising the same as active ingredient.
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Page/Page column 30
(2008/06/13)
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- Asymmetric synthesis of the cis- And trans-stereoisomers of 4-aminopyrrolidine-3-carboxylic acid and 4-aminotetrahydrofuran-3-carboxylic acid
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The diastereoselective conjugate addition of lithium (S)-N-benzyl-N- α-methylbenzylamide has been successfully applied to the first asymmetric syntheses of cis-(3S,4R)- and fraBs-(3R,4R)-4-arninotetrahydrofuran-3-carboxylic acids (26% and 25% overall yield respectively, >98% d.e. and >97% e.e. in each case). Furthermore, the most efficient asymmetric synthesis to date of cis-(3R,4R)- and trans-(3R,4S)-4-aminopyrrolidine carboxylic acids is delineated: for cis-(3R,4R), four steps, >98% d.e., 52% overall yield; for trans-(3R,4S), five steps, >98% d.e., 50% overall yield.
- Bunnage, Mark E.,Davies, Stephen G.,Roberts, Paul M.,Smith, Andrew D.,Withey, Jonathan M.
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p. 2763 - 2776
(2007/10/03)
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