- Intermediate 2,2-dimethyl cyclopropane methyl formate synthesizing method
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The invention discloses an intermediate 2,2-dimethyl cyclopropane methyl formate synthesizing method. According to the synthesizing method, CuCl, dichloromethane, methyl senecioate, CH2Br2, aluminum isopropoxide, SBA-15 and CH3COCl are utilized as main raw materials. According to the synthesizing technology disclosed by the invention, methyl senecioate and dibromomethane can obtain a target product through cyclopropanation reaction under the catalyst action; the reaction can be obviously affected by whether a catalyst exists or not, and the kind of the used catalyst also has an obvious effecton the reaction; thus, the problems that a catalyst in a traditional preparation mode has low activity, a raw material conversion rate is low and the like are solved, no toxic and harmful matters aregenerated in a production process, a product yield is remarkably improved, and the intermediate 2,2-dimethyl cyclopropane methyl formate synthesizing method can be applied to production.
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Paragraph 0010; 0011; 0012; 0013; 0014; 0015; 0016-0032
(2018/10/26)
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- Nucleophilic intermolecular chemistry and reactivity of dimethylcarbene
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Experimental and computational studies find that dimethylcarbene (DMC), the parent dialkylcarbene, is both predicted to be and functions as a very reactive nucleophilic carbene in addition reactions with five simple alkenes. Activation energies and enthal
- Cang, Hui,Moss, Robert A.,Krogh-Jespersen, Karsten
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p. 2730 - 2737
(2015/03/04)
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- A new approach to the synthesis of cilastatin, an inhibitor of renal dipeptidase
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A convenient preoarative synthesis of cilastatin, an inhibitor of renal dipeptidase used in drugs with the antibiotic imipenem, has been elaborated.The key intermediate in this synthesis is 2-amino-7-chloroheptanoic acid prepared by oxidative cleavage of cycloheptanone followed by bromination of 7-chloroheptanoyl chloride with subsequent amination of the 2-bromo-7-chloroheptanoic acid thus formed.All of the stages of the new synthesis are easily performed, as is the isolation of the intermediate products, and they do not require any organometallic reagents. - Key words: cilastatin, (R)-cysteine, 7-chloroheptanoic acid, 2-amino-7-chloro-2-heptenoic acid, 2,2-dimethylcyclopropanecarbonyl chloride; oxidation, bromination, amination, cyclopropanation.
- Vinogradov, M. G.,Kaigorodova, L. N.,Chel'tsova-Bebutova, G. V.,Gorshkova, L. S.,Starostin, E. K.,et al.
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p. 167 - 171
(2007/10/02)
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- Carbonium Ion Rearrangements Controlled by the Presence of a Silyl Group
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γ-Silyl tertiary alcohols rearrange in protic acid with 1,2-shift of hydride, phenyl, or alkyl groups, and loss of the silyl group to give alkenes.The placing of the silyl group thus controls the carbonium ion rearrangement in a preparatively useful way.Methoxycarbonyl groups do not migrate; instead, cyclopropanes are formed, except when the conformation suitable for cyclopropane formation is unattainable.When the alkene product is 2,2-disubstituted, it can be reprotonated under the reaction conditions and does not therefore always survive.This can be avoided by carrying out the reaction using a Lewis acid on the silyl ether.The starting γ-silyl alcohols are prepared by a variety of versatile methods.
- Fleming, Ian,Patel, Shailesh K.,Urch, Christopher J.
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p. 115 - 124
(2007/10/02)
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- Menthyl 2,2-dimethylcyclopropanecarboxylate and resolution of the same
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An ester obtained from 2,2-dimethylcyclopropanecarboxylic acid and optically active menthol, represented by the formula, STR1 is effectively resolved into diastereomers, which upon hydrolysis give optically active 2,2-dimethylcyclopropanecarboxylic acid.
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