- Synthetic method of 2, 4-dihydroxyl-3, 3-dimethyl butyric acid
-
The invention discloses a synthetic method of 2, 4-dihydroxyl-3, 3-dimethyl butyric acid. The synthetic method of 2, 4-dihydroxyl-3, 3-dimethyl butyric acid comprises following steps: 1), isobutyraldehyde and ethyl oxalyl monochloride are subjected to aldol condensation under the effect of RM to generate 3, 3-dimethyl-2, 4-dioxo ethyl butyrate, wherein M is used for representing an alkali metal, and R is used for representing alkyloxy, hydrogen, amino, or alkyl; 2), 3, 3-dimethyl-2, 4-dioxo ethyl butyrate is subjected to reduction reaction to generate 2, 4-dihydroxyl-3, 3-dimethyl ethyl butyrate, and 2, 4-dihydroxyl-3, 3-dimethyl ethyl butyrate is subjected to hydrolysis so as to obtain a target product. According to the synthetic method, isobutyraldehyde and ethyl oxalyl monochloride are adopted as initial raw materials, aldol condensation reaction, reduction reaction, and hydrolysis reaction are adopted to obtain the target product, compared with the prior art, the advantages of the synthetic method are that: no hypertoxic raw material is adopted, operation safety is high, reaction conditions are not server, and operation is simple, and is convenient to control.
- -
-
Paragraph 0015; 0037; 0041; 0042; 0046; 0047-0051; 0052-0056
(2019/10/10)
-
- Environment-friendly synthesis method of D-calcium pantothenate intermediate D, L-pantoyl lactone
-
The invention relates to an environment-friendly synthesis method of a D-calcium pantothenate intermediate D, L-pantoyl lactone. According to the method, isobutyraldehyde and glyoxylic acid are utilized to prepare 2-hydroxy-3-methyl-3-formyl butyric acid (II) under the catalytic action of organic alkali in an aldol condensation mode, then catalytic hydrogenation is conducted, 2,4-dyhydroxy-3,3-dimethyl butyric acid (III) is obtained, after the catalyst is filtered out, the filtrate is subjected to lactonization under the acidic condition, and the D, L-pantoyl lactone is obtained. The raw materials used for the method are cheap and easy to obtain, the technological process is short, product cost is low, less wastewater is generated, and treatment is easy to conduct; highly toxic raw materials are avoided, and operation is safe.
- -
-
Paragraph 0036; 0045-0052
(2017/04/18)
-
- A new chemo-enzymatic route to chiral 2-hydroxy-4-phenylbutyrates by combining lactonase-mediated resolution with hydrogenation over Pd/C
-
A new chemo-enzymatic route to both isomers of 2-hydroxy-4-phenylbutyric acid is reported. The key step is the lactonase-catalyzed hydrolysis of cis- and trans-2-hydroxy-4-phenyl-4-butyrolactones followed by hydrogenation over Pd/C to afford optically pure 2-hydroxy-4-phenylbutyric acid.
- Chen, Bing,Yin, Hai-Feng,Wang, Zhen-Sheng,Liu, Jia-Ying,Xu, Jian-He
-
supporting information; experimental part
p. 2754 - 2756
(2010/09/04)
-
- Nopinylamines
-
The nopinylamines of the general formula I STR1 where R1 and R2 are hydrogen or alkyl of 1 to 5 carbon atoms, and the salts of these amines with mineral acids and with alkylcarboxylic acids of 1 to 4 carbon atoms. The manufacture of I from nopinone (II) STR2 by aminating hydrogenation with amines (III) STR3 The use of I for resolving racemates of acid or acid-forming compounds, especially of DL-pantolactone.
- -
-
-