- Cu-OMS-2-catalyzed decarboxylation-acetoxylation of (3R,4R)-4-acid-3-[(R)- 1-((t-butyl-dimethylsilyl)oxy)-ethyl]-1-methoxyphenyl-2-azetidinone with NaBrO3/NaOAc
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(3R,4R)-4-Acetoxy-3-[(R)-1((t-butyldimethylsilyl)oxy)-ethyl] -1-methoxyphenyl-2-azetidinone (an important precursor for the synthesis of carbapenem antibiotics) was synthesized under mild and green conditions catalyzed by Cu-OMS-2. Normal to excellent iso
- Li, Guixian,Peng, Bingbing,Mao, Zhihong,Qian, Guang,Ji, Shengfu
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Read Online
- Preparation method of azetidinone compound and preparation method 4 - acyloxy-azetidinone compound
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The invention provides a preparation method of a azetidinone compound and a preparation method of 4 - acyloxy-azetidinone compound. The preparation method comprises the following steps S1, an epoxy amide compound reacts with I alkali reagents to form a ring reaction, and first 1st reaction systems are obtained. Step S2: The first reaction system is subjected to hydroxyl protection reaction with a raw material including a silanization reagent and a nitrogen-containing basic organic matter to obtain second reaction systems. In step S3, second reaction system and second base reagent are subjected to isomerization reaction to obtain the azetidinone compound, wherein the epoxy amide compound has the structure shown VI, the separation process of the isomer product of the structure shown II and formula III IV is avoided, and the selectivity and yield of the azetidinone compound are improved.
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Paragraph 0101-0102
(2021/11/19)
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- Practical synthetic approach to 4-acetoxy-2-azetidinone for the preparation of carbapenem and penem antibiotics
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A practical synthesis of 4-acetoxy-2-azetidinone useful for the preparation of carbapenem- and penem-type antibiotics is described. The synthesis has advantages such as avoiding the tedious and costly column chromatographic or recrystallized separation steps for diastereomers. The overall yield of the product is greatly improved and the process is also more economical for large-scale production. In addition, the mechanism for oxidative decarboxylation is also present. Springer Science+Business Media B.V. 2011.
- Zhou, Guo-Bin,Guan, Yue-Qing,Tang, He,Zhao, Yan-Bin,Yang, Li-Rong
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experimental part
p. 251 - 259
(2012/05/20)
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- METHOD FOR PREPARING 4-ACETOXYAZETIDINONE AND DERIVATIVES THEREOF
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The present invention relates to a method for preparing 4-acetoxyazetidinone and derivatives thereof, and in particular to the preparation method comprising the steps of: dissolving a compound which is substituted with a ketone derivative at the C-4 position of beta-lactam in a water soluble organic solvent; and adding a peroxidant, acetic acid salt or an inorganic salt thereto to perform a Baeyer-Villiger oxidation reaction and an acetoxy substitution reaction in a reactor in situ. Thus, according to the preparation method of the present invention, 4-acetoxyazetidinone and derivatives thereof can be easily prepared with high purity and high yield.
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Page/Page column 12-13
(2008/06/13)
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- PROCESSES FOR THE PREPARATION OF PENEMS AND ITS INTERMEDIATE
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The present invention relates to a process for the preparation of 4-acetoxy azetidinone of Formula I, wherein R2 is hydrogen or a suitable amino protecting group and P is suitable hydroxy protecting group, and to the use of these compounds as intermediates for the preparation of ?-lactam antibiotics that possess the carbapenem and penem ring systems. 4-acetoxy azetidinone of Formula I is a key intermediate in the synthesis of ?-lactam antibiotics which are commonly prescribed antimicrobial agents having activity against a wide range of both Gram-positive and Gram-negative bacteria.
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Page/Page column 22
(2008/06/13)
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- A NEW ENANTIO AND DIASTEREOSELECTIVE SYNTHESIS OF 2-AZETIDINONES AS USEFUL INTERMEDIATES OF β-LACTAM ANTIBIOTICS
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An expeditious enantio and diastereoselective route to β-lactam synthons has been developed; two novel key radical reactions allowed us to obtain two useful intermediates in the synthesis of thienamycin and PS-5.
- Bonini, Carlo,Fabio, Romano Di
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p. 815 - 818
(2007/10/02)
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- Asymmetric Synthesis of (1'R,3R,4R)-4-Acetoxy-3(1'-((tert-butyldimethylsilyl)oxy)ethyl)-2-azetidinone and Other 3-(1'-Hydroxyethyl)-2-azetidinones from (S)-(+)-Ethyl 3-Hydroxybutanoate: Formal Total Synthesis of (+)-Thienamycin
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The synthesis of (1'R,3R,4R)-4-acetoxy-3-(1'-((tert-butyldimethylsilyl)oxy)ethyl)-2-azetidinone, an important precursor for synthesis of carbapenems and penems, is detailed.The methodology utilized relies on the addition, cyclization reaction between the dianion of (S)-(+)-ethyl 3-hydroxybutanoate and N-arylaldimines.The syntheses of other useful optically active 3-(hydroxyethyl)-2-azetidinones are presented.A study of factors influencing the stereochemistry in the addition, cyclization reaction for the formation of 3-(1'-hydroxyethyl)-2-azetidinones is detailed.
- Georg, Gunda I.,Kant, Joydeep,Gill, Harpal S.
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p. 1129 - 1135
(2007/10/02)
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