cas 76855-69-1, (3S,4R)-4-Acetoxy-3-[(R)-1-(tert-butyldimethylsilyloxy)ethyl]azetidin-2-one

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Method for removing P-methoxyphenyl protecting group on amide group
The invention provides a method for removing p-methoxyphenyl protecting groups on amide groups. The method comprises the steps of sequentially performing ozonation reaction and quenching treatment on a substrate and ozone in the presence of an organic solvent to obtain an oxidation intermediate, wherein an amide group in the substrate is protected by a p-methoxyphenyl group. The oxidation intermediate is subjected to a reduction reaction with carbon monoxide or a mixed gas containing carbon monoxide to remove p-methoxyphenyl. After the substrate and the ozone are subjected to ozonation reaction, the product system of the ozonation reaction is quenched, and then the quenched oxidized intermediate and carbon monoxide are subjected to a reduction reaction to remove p-methoxyphenyl groups to obtain the required amide organic matters. To the method for removing the P-methoxyphenyl protecting group on the amide group, thiourea is not needed, so that the whole process does not generate sulfur-containing wastewater, the cost is lower, and the method is more environmentally friendly.
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Paragraph 0031-0057

(2021/10/27)

Preparation method of azetidinone compound and preparation method 4 - acyloxy-azetidinone compound
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; 0103; 0104

(2021/11/19)

Preparation method of 4AA
The invention discloses a preparation method of 4AA. The preparation method comprises the following steps: S1, preparing a first intermediate from benzamide and a formaldehyde aqueous solution; S2, preparing a second intermediate from the first intermediate, thionyl chloride, toluene and n-heptane; S3, preparing a third intermediate from the second intermediate, methyl acetoacetate, sodium methoxide, toluene, diluted hydrochloric acid and isopropanol; S4, preparing a fourth intermediate from the third intermediate, reductase, ethyl acetate, saturated sodium bicarbonate and saturated salt water; S5, preparing a fifth intermediate from the fourth intermediate, imidazole, TBSCL and methylbenzene; S6, preparing a sixth intermediate from the fifth intermediate, ethanolamine, methanol and n-heptane; S7, preparing a seventh intermediate by using the sixth intermediate, a Grignard reagent and n-heptane; and S8, preparing 4AA from the seventh intermediate, ruthenium trichloride, potassium acetate, ethyl acetate, acetic acid and a peracetic acid solution.
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Paragraph 0016; 0018; 0020-0021; 0023-0024; 0026

(2021/07/28)

Preparation method of penem antibiotic intermediate 4 - acetoxy azacyclobutanone (by machine translation)
The invention discloses a preparation method of penem antibiotic intermediate 4 - acetoxy azacyclobutanone (4 - AA), and specifically discloses a preparation method of 4 - acetoxyazacyclobutanone (4 - AA) in an organic solvent under the action of a metal catalyst and an oxidant, and has the characteristics of being economical and efficient, small in environmental pollution and high in yield 4 - 4 - AA. (by machine translation)
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Paragraph 0033; 0036-0039; 0040; 0043-0046; 0054-0060

(2020/09/30)

Synthetic method of penem drug intermediate
The invention discloses a method for synthesizing biapenem medicine intermediates. The method has the advantages that the biapenem medicine intermediates 4-AA are prepared from (R)-3-polyhydroxybutyrate which is a raw material, and the raw material in the routes is inexpensive, is easily available and can be substantially purchased; the method includes simple steps, the various steps are high in yield, and reaction is simple; chiral reagents and chiral resolution are omitted, accordingly, the method is low in cost and high in yield, and reaction conditions are easily available.
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(2020/05/19)

The photocatalysis removing N - alkyl preparation penem pharmaceutical intermediate 4 - AA method (by machine translation)
A photocatalytic removing N - alkyl preparation penem pharmaceutical intermediate 4 - AA of the method, the preparation step comprises: the compound I radix Aconiti Kusnezoffii alcohol solvent of the solution to form solution; to the step (1) are added in the solution in the titanium dioxide catalyst; ultraviolet light for the irradiation step (2) of the reaction material, temperature control in the 10 °C within, then according to the thin-layer chromatography (TLC detection) to control the speed of the material point of the illumination reaction time; after the reaction, membrane filtration or centrifugal separating titanium dioxide catalyst, part of the solvent is distilled under reduced pressure recovery, then adding de-ionized water, precipitated product, then recrystallized refining to obtain the target product. L - threonine line can overcome the preparation 4 - AA final one-step in the method of removing alkyl N - the defect of complex, simple, efficient, non-metal pollution, no waste water discharge, reducing the 4 - AA synthesis cost, to reduce the environmental pressure have obvious effect; its reaction equation is as follows: (by machine translation)
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Paragraph 0025; 0026-0027; 0029; 0031

(2019/01/14)

Method for reduction preparation of 4-AA with inorganic reducing agent
The invention discloses a method for reduction preparation of (3R,4R)-4-acetoxyl-3-[(R)-1-[(terbutyldimethylsilyl)oxy-ethyl]-2-azetidinone with an inorganic reducing agent. The inorganic reducing agent is reductive metal powder. The method includes the following steps that firstly, the inorganic reducing agent is pretreated, wherein the reductive metal powder is placed in an acidic or alkaline solution to be activated to obtain activated metal powder; secondly, ozone is introduced into a solution of a compound I for an oxidation reaction to obtain an ozonization reaction solution; thirdly, theactivated metal powder obtained in the first step is added into the ozonization reaction solution obtained in the second step for a reduction reaction, and (3R,4R)-4-acetoxyl-3-[(R)-1-[(terbutyldimethylsilyl)oxy-ethyl]-2-azetidinone is obtained, wherein the structural formula of the compound I is shown in the description. The method only needs one-step reduction, the amount of wastewater can be reduced, the content of ammonia nitrogen and sulfur in the wastewater is reduced, and the COD value of the wastewater is reduced.
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Paragraph 0035-0040; 0041-0046; 0047-0052; 0053-0067

(2018/03/24)

Process and device for synthesizing (3R, 4R)-4-acetoxyl-3-[(R)-1-tert-butyl dimethyl silica ethyl]-2-azetidinone
The invention discloses a process and a device for synthesizing (3R, 4R)-4-acetoxyl-3-[(R)-1-tert-butyl dimethyl silica ethyl]-2-azetidinone. 4-AA industrial products can be synthesized by the aid of continuous reaction technologies for series connection circuit reactors. The process includes dissolving a raw material (3R, 4R)-3-[(R)-1-tert-butyl dimethyl silica ethyl]-4-acetoxyl-1-(4-methoxy phenyl)-2-azetidinone by the aid of methanol; allowing series connection circuit reaction devices to carry out oxidation deprotection on PMP protecting groups in the raw material by the aid of ozone; carrying out reduced-pressure distillation to remove the methanol and then adding water to the raw material to obtain 4-AA crude products; re-crystallizing the crude products to obtain 4-AA products. The process and the device have the advantages that the process is simple, safe in oxidation deprotection reaction operation, short in reaction time and low in running cost; the reaction yield can be greatly increased, and the mass yield of the 4-AA products is higher than 69%.
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Paragraph 0050-0058

(2017/01/26)

A METHOD OF PREPARATION OF (1'R,3R,4R)-4-ACETOXY-3-(1'-(TERT-BUTYLDIMETHYLSILYLOXY)ETHYL)-2-AZETIDINONE, A PRECURSOR FOR CARBAPENEM ANTIBIOTICS SYNTHESIS
The subject of the present invention is a method of preparation of (1'R,3R,4R)-4-acetoxy-3-(1'- (tert-butyl-dimethylsilyloxy)ethyl)-2-azetidinone defined by the formula (1) which is a basic chiral building block in the synthesis of carbapenem antibiotics.
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Page/Page column 12-13

(2014/07/08)

A practical preparation of the key intermediate for penems and carbapenems synthesis
A novel, practical and stereoselective synthesis of (3R,4R)-4-acetoxy-3-(R) -1-(t-butyldimethylsilyloxy)ethyl-2-azetidinone, a key intermediate in the preparation of β-lactam antibiotics is reported. The crucial step of the synthesis is based on the Cu(I)-mediated Kinugasa cycloaddition/rearrangement cascade between silyl protected (R)-3-butyn-2-ol and the nitrone derived from benzyl hydroxylamine and benzyl glyoxylate. The obtained adduct is subjected to debenzylation with sodium, or lithium in liquid ammonia followed by oxidation with lead tetraacetate to afford the final product.
Grzeszczyk, Barbara,Stecko, Sebastian,Mucha, Lukasz,Staszewska-Krajewska, Olga,Chmielewski, Marek,Furman, Bartlomiej
p. 161 - 163
(2013/08/25)

Practical synthetic approach to 4-acetoxy-2-azetidinone for the preparation of carbapenem and penem antibiotics
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
experimental part
p. 251 - 259
(2012/05/20)

Efficient asymmetric synthesis of (2R,3R)-3-{(1R)-1-[tert-Butyl(dimethyl)- siloxy]ethyl}-4-oxoazetidin-2-yl acetate
(2R,3R)-3-{(1R)-1-[tert-Butyl(dimethyl)siloxy]ethyl}-4-oxoazetidin-2-yl acetate was efficiently prepared from l-ascorbic acid. The key steps were the a highly diastereoselective [2 + 2] cycloaddition of diketene with an (S)-glyceraldehyde-derived ald?imine to give the ketone, stereoselective titanium tetrachloride mediated asymmetric reduction to give the corrsponding S-configured alcohol, and Mitsunobu inversion of the latter to give the desired R-configured alcohol. Georg Thieme Verlag Stuttgart ? New York.
Huang, Jian-Ping,Zhao, Lei,Gu, Shuang-Xi,Wang, Zhong-Hua,Zhang, Hao,Chen, Fen-Er,Dai, Hui-Fang
p. 555 - 562
(2011/04/15)

A catalytic asymmetric route to carbapenems
Image Presented Efficient syntheses of N-acetyl thienamycin and epithienamycin A in their readily deprotected form are reported where three contiguous stereocenters are established in a single catalytic asymmetric azetidinone-forming reaction. These examples are a template for synthesizing C-5/C-6 cis or trans carbapenems with independent control of the C-8 stereocenter. A library of oxidatively and sterochemically defined azetidinone precursors to a variety of naturally occurring carbapenems and potential biosynthetic intermediates has been prepared to facilitate studies of carbapenem antibiotic biosynthesis.
Bodner, Micah J.,Phelan, Ryan M.,Townsend, Craig A.
p. 3606 - 3609
(2011/03/17)

Novel stereoselective synthesis of 4-acetoxyazetidinone from methyl 6,6-dibromopenicillanate: Key intermediate for the preparation of carbapenem antibiotics
A novel and practical process for the completely stereoselective synthesis of carbapenem key intermediate (3R,4R)-4-acetoxy-3-[(R)-1-((t- butyldimethylsilyl)oxy)ethyl]-2-azetidinone has been developed by starting from methyl 6,6-dibromopenicillanate. Aldol condensation of the magnesium enolate derived from the-sulfoxide with acetaldehyde allows for the stereospecific introduction of a 1-R-hydroxyethyl substituent as C-6. The hydroxyethylated product was reduced with Zn-NH4OAc in tetrahydrofuran (THF) efficiently to give methyl 6-(1-hydroxyethyl)-penicillanate-1-oxide. Protection of the hydroxy group followed by treatment with 2-mercaptobenzothiazole afforded the dithioazetidinone, which was easily reduced and methylated to give 4-methylthioazetidinone. Then this compound was oxidized with permanganate to selectively remove the side chain at the N-position to afford the 4-methylthioazetidinone derivative. A facile conversion of the methylthio group to acetoxy for a practical synthesis of 4-acetoxyazetidinone was also reported. This method provided an efficient and cost-effective process with good overall yield and excellent stereoselectivity.
Long, Bohua,Xiang, Jiannan
experimental part
p. 4019 - 4029
(2009/12/24)

Novel synthesis of (3R,4R)-4-acetoxy-3-[1′(R)-tert- butyldimethylsilyloxyethyl] azetidin-2-one: A key intermediate for penem and carbapenem synthesis
Diastereoselective synthesis of (3R,4R)-4-acetoxy-3-[1′(R)-tert- butyldimethylsilyloxyethyl] azetidin-2-one (AOSA) using (-)-D-2,10-camphorsultam as a key and recyclable chiral auxiliary is described. Copyright Taylor & Francis Group, LLC.
Singh, Santosh Kumar,Singh,Byri,Satish,Dhamjewar, Ravi,Gopalan
p. 456 - 464
(2008/04/01)

METHOD FOR PREPARING 4-ACETOXYAZETIDINONE AND DERIVATIVES THEREOF
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)

Ruthenium-catalyzed oxidative cyanation of tertiary amines with molecular oxygen or hydrogen peroxide and sodium cyanide: Sp3 C-H bond activation and carbon-carbon bond formation
Ruthenium-catalyzed oxidative cyanation of tertiary amines with molecular oxygen in the presence of sodium cyanide and acetic acid gives the corresponding α-aminonitriles, which are highly useful intermediates for organic synthesis. The reaction is the first demonstration of direct sp3 C-H bond activation α to nitrogen followed by carbon-carbon bond formation under aerobic oxidation conditions. The catalytic oxidation seems to proceed by (i) α-C-H activation of tertiary amines by the ruthenium catalyst to give an iminium ion/ruthenium hydride intermediate, (ii) reaction with molecular oxygen to give an iminium ion/ruthenium hydroperoxide, (iii) reaction with HCN to give the α-aminonitrile product, H2O2, and Ru species, (iv) generation of oxoruthenium species from the reaction of Ru species with H2O2, and (v) reaction of oxoruthenium species with tertiary amines to give α-aminonitriles. On the basis of the last two pathways, a new type of ruthenium-catalyzed oxidative cyanation of tertiary amines with H2O2 to give α-aminonitriles was established. The α-aminonitriles thus obtained can be readily converted to α-amino acids, diamines, and various nitrogen-containing heterocyclic compounds.
Murahashi, Shun-Ichi,Nakae, Takahiro,Terai, Hiroyuki,Komiya, Naruyoshi
scheme or table
p. 11005 - 11012
(2009/02/05)

USAGE OF POLY-3-HYDROXYALKANOATES IN PREPARATION OF BETA-LACTAM COMPOUNDS
The present invention discloses the usage of Poly-3-hydroxybutyrates P(3HB) in preparation of β-lactam compounds and the method for the preparation of β-lactam compounds of formula(I) using Poly-3-hydroxybutyrates P(3HB) as followed: wherein: R is R1□ R2□ R3 are lower linear or branched C1-C4 alkyl. It is convenient to synthesize the said compound of formula (I) with the present method. Compared with the previous ones, the present method has less steps and higher yields. Meanwhile, it also avoids the use of the reagents of the environmental for pollution and high cost, so as to reduce the cost and pollution
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Page/Page column 6-7

(2008/12/08)

PROCESSES FOR THE PREPARATION OF PENEMS AND ITS INTERMEDIATE
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 23

(2008/06/13)

Stereoselective mannich-like reactions of ester enolates generated on sugar templates: A novel access to a key intermediate for 1β-methylcarbapenem synthesis
The Mannich-like reactions of the enolates generated from 2,3-di-O-protected 6-deoxy-4-O-propionyl-α-D-glucopyranosides with (3R,4R)-4-acetoxy-3-((R)-1-(t-butyldimethylsilyloxy)ethyl ]azetidin-2-one were investigated. The corresponding 2,3-di-O-methyl derivative provided the Mannich adduct in good to excellent stereoselectivity. From the major adduct, the azetidin-2-one incorporating an α-methyl acetic acid side chain at the C-4 position with ?-configuration was obtained by alkaline hydrolysis. This product, (3S,4S)-3-[(R)-1-(t-butyldimethylsilyloxy)ethyl 1-4-1(R)-1-carboxyethylJazetidin-2-one, is a useful intermediate for the 1 ?-methylcarbapenem synthesis.
Sasaki, Daisuke,Sawamoto, Daisuke,Takao, Ken-ichi,Tadano, Kin-ichi,Okue, Masayuki,Ajito, Keiichi
p. 103 - 110
(2008/02/13)

Regioselective Baeyer-Villiger Oxidation in 4-Carbonyl-2-azetidinone Series: A Revisited Route toward Carbapenem Precursor
A novel synthesis of acetoxyazetidinone 2 is presented. The azetidinone ring of compounds 7 is formed by C-3/C-4 cyclization of (2R,3R)-epoxybutyramide precursors 6, N-protected with a benzhydryl group. N-Deprotection by photoactivated bromination and acidic treatment leads to compounds 10 with various CO-R substituents at C-4. Transformation of these substituents by Baeyer-Villiger oxidation gives the desired regioisomer 11 with the cyclopropyl side-group which is the only group (among R = H, Ph, t-Bu, i-Pr, c-Pr) able to satisfy both the steric requirements of the cyclization step and the electronic requirements of the oxidative rearrangement step.
Laurent, Mathieu,Ceresiat, Marcel,Marchand-Brynaert, Jacqueline
p. 3194 - 3197
(2007/10/03)

Highly diastereoselective addition of a chiral ketene silyl acetal to nitrones: Asymmetric synthesis of β-amino acids and key intermediates of β- lactam antibiotics
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Ohtake, Hiroaki,Imada, Yasushi,Murahashi, Shun-Ichi
p. 3790 - 3791
(2007/10/03)

A practical synthesis of a key intermediate for the production of β- lactam antibiotics
N-(p-methoxyphenyl)-hexahydro-1,3,5-triazine in presence of a Lewis acid and (R)-3-(t-butyldimethylsilyloxy)butyric acid chloride with Et3N directly furnish (3S,1'R)-N-p-methoxyphenyl-3-(l-t- butyldimethylsilyloxy)ethylazetidin-2-one with good diastereoselectivity. This product is transformed into the 4-acetoxy-azetidinone 1, a key intermediate in the synthesis of β-lactam antibiotics.
Cainelli, Gianfranco,Galletti, Paola,Giacomini, Daria
p. 7779 - 7782
(2007/10/03)

A facile synthesis of the key intermediate for penems, carbapenems, and related β-lactam antibiotics
Michael addition of the hydroxylamine 14 to the N-acryloyl-1,3-benzoxazinone 13 followed by the titanium enolate-mediated aldol reaction with acetaldehyde gave syn-aldol 16 in a high yield with excellent diastereoselectivity. Silylation of 16 followed by treatment with BnOLi and acetylation gave benzyl ester 19 together with the recovered chiral auxiliary 12 both in high yields. Mild hydrogenolysis of 19 furnished the β-amino acid derivative 20 which was transformed into acetoxyazetidinone 3, the key intermediate of penems 1 and carbapenems 2.
Seki, Masahiko,Yamanaka, Takeshi,Miyake, Tsutomu,Ohmizu, Hiroshi
p. 5565 - 5568
(2007/10/03)

Substituted acetoxyazetidinone derivatives and process for preparing 4-acyloxyazetidinone derivatives
A process for preparing a 4-acyloxyazetidinone or a derivative thereof represented by formula (IV): STR1 wherein R1 represents a hydrogen atom, a lower alkyl group, a hydroxyethyl group, or a protected hydroxyethyl group; R3 represents an alkyl group having from 1 to 10 carbon atoms which may be substituted with a halogen atom, a cyano group, a lower alkoxy group or a phenyl group, or a substituted or unsubstituted phenyl group, provided that the α-positioned carbon atom of said alkyl group should not have more than two halogen atoms; and R4 represents a hydrogen atom, a lower alkyl group, or a lower alkoxycarbonyl group, which is useful as an intermediate for penem antibiotics is disclosed, comprising reacting azetidinone or a derivative thereof represented by formula (II): STR2 wherein R1 is as defined above, and R2 represents a hydrogen atom, a lower alkyl group, a lower alkoxycarbonyl group, or a carboxyl group, with a carboxylic acid represented by formula (III): wherein R3 is as defined above, in the presence of (1) a transition metal compound selected from a ruthenium compound, an osmium compound, and a cobalt compound, (2) an aldehyde having 2 or more carbon atoms, provided that the carbon atom at the α-position thereof should not have two or more halogen atoms, and (3) oxygen. The compound (IV) can be prepared with safety through simple and easy operations.
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(2008/06/13)

Copper-assisted substitution reaction for phenylthio group of a 4- phenylthioazetidinone derivative
The phenylthio group of 4-phenylthioazetidinone (1) was readily substituted with copper(I) salts of carboxylates, thiocarboxylates, and copper(I) enolates of malonates and β-ketoesters to give synthetic intermediates (3 and 4) for penem and carbapenem antibiotics.
Shimamoto,Inoue,Yoshida,Tanaka,Nakatsuka,Ishiguro
p. 5887 - 5888
(2007/10/02)

PHOTO-OXIDATIVE CLEAVAGE OF A FURAN-AZETIDINONE CARBON-CARBON BOND: A SYNTHESIS OF 4-ACETOXYAZETIDINONE
A stereoselective synthesis of the 4-acetoxyazetidinione (1) from methyl 3(R)-hydroxybutyrate is reported.The synthesis involved stereoselective preparation of a 4-(2-furanyl)azetidinone that was allowed to react with singlet oxygen.The resulting endoperoxide intermediates underwent direct rearrangement to an acyloxyazetidinone that on reaction with sodium acetate gave 1 in modest yield.An improved yield of 1 was obtained by treatment of the endoperoxides with hydrogen peroxide followed by acetic anhydride to give an α-alkoxy acylperoxide that underwent thermal rearrangement to 1.
Lynch, Joseph E.,Laswell, William L.,Volante, Ralph P.,Reamer, Robert A.,Tschaen, David M.,Shinkai, Ichiro
p. 1029 - 1037
(2007/10/02)

Acetyloxylation process for producing 4-acetoxyazetidinones with osmium catalyst
A process for producing a 4-acetoxyazetidinone represented by formula (I): STR1 wherein Z represents a hydrogen atom, a lower alkyl group, or a protected or unprotected hydroxyethyl group; and W represents a hydrogen atom, a lower alkyl group, or a group of --COOR1, wherein R1 represents a lower alkyl group, is disclosed, which comprises reacting an azetidinone represented by formula (II): STR2 wherein Z is as defined above; and Y represents a hydrogen atom, carboxyl group, a lower alkyl group, or a group of --COOR1, wherein R1 represents a lower alkyl group, with acetic acid and an oxidizing agent in the presence of, as a catalyst, an anhydrous or hydrous osmium compound represented by OsX3, wherein X represents a chlorine atom, a bromine atom, or an iodine atom.
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(2008/06/13)

A highly stereoselective synthesis of the 1β-methylcarbapenem key intermediate from (R)-3-hydroxybutyric acid
(3R,4R)-4-Acetoxy-3-[(R)-1-(formyloxy)ethyl]-2-azetidinone 6 could be prepared highly stereoselectivity from (R)-3-hydroxybutyric acid by employing the [2+2]-cycloaddition reaction of chlorosulfonyl isocyanate with the 2H,4H-1,3-dioxin derivative and the Baeyer-Villiger reaction accompanying novel cleavage of the acetal moiety. The Reformatsky reaction of 6 with sterically crowded 3-(2-bromopropionyl)-2-oxazolidone derivatives readily afforded the title key intermediate after sequential chemical manipulations.
Kobayashi, Yuko,Ito, Yoshio,Terashima, Shiro
p. 55 - 66
(2007/10/02)

An efficient synthesis of 4-heterofunction-substituted 3-(1-hydroxy)ethylazetidin-2-ones from 3-(1-hydroxy)ethyl-4-phenylsulfinylazetidin-2-one by reaction with silylated heteronucleophiles
3-(1-tert-Butyldimethylsiloxy)ethyl-4-sulfinylazetidin-2-one was reacted with silylated N-, S-, O-, and P-nucleophiles in the presence of a catalytic amount of ZnI2 to give the corresponding trans-4-heterofunction-substituted azetidin-2-ones in high yields.
Kita,Shibata,Yoshida,Tohjo
p. 1733 - 1736
(2007/10/02)

OSMIUM-CATALYZED OXIDATION OF β-LACTAMS WITH PEROXIDES
Osmium-catalyzed oxidation of β-lactams with peroxides in acetic acid gives the corresponding 4-acetoxy β-lactams, which are versatile synthetic intermediate of carbapenem antibiotics, in good to excellent yields.
Murahashi, Shun-Ichi,Saito, Takao,Naota, Takeshi
p. 2145 - 2148
(2007/10/02)

Ruthenium-catalyzed oxidation of β-lactams with molecular oxygen and aldehydes
The RuCl3 catalyzed reaction of β-lactams in the presence of acetaldehyde and molecular oxygen in an acid and ethyl acetate under buffer conditions gives the corresponding 4-acyloxy β-lactams highly efficiently.
Murahashi,Saito,Naota,Kumobayashi,Akutagawa
p. 5991 - 5994
(2007/10/02)

NEW SYNTHESIS OF 4-ACETOXY-2-AZETIDINONES BY USE OF ELECTROCHEMICAL OXIDATION
4-Acetoxy-2-azetidinone was synthesized from 4-carboxy-2-azetidinone by Kolbe-type electrolysis.Optically pure 4-acetoxy-3--2-azetidinone, which is an important intermediate for the synthesis of thienamycin, and (+)-PS-5 were synthesized by use of this method.
Mori, Miwako,Kagechika, Katsuji,Sasai, Hiroaki,Shibasaki, Masakatsu
p. 531 - 540
(2007/10/02)

Synthetic studies of carbapenem and penem antibiotics. I. Facile synthesis of a key intermediate: 4-Acetoxy-3-(1-hydroxyethyl)-2-azetidinone
A highly efficient synthesis of (3R,4R)-4-acetoxy-3-[(R)-1-hydroxyethyl]-2-azetidinone, which is a key intermediate for the synthesis of carbapenem and penem antibiotics, was accomplished. It was found that oxymercuration-reduction of easily obtainable 4-alkyloxycarbonyl-1-(di-p-anisylmethyl)-3-ethenyl-2-azetidinone could be employed as a key stereoselective reaction. The chiral starting material was obtained by optical resolution or asymmetric (2 + 2) cycloaddition. The desired product was afforded in four steps, that is, oxymercuration-reduction, oxidative decarboxylation, protection of the hydroxy group and removal of the N-protecting group.
Sunagawa,Matsumura,Enomoto,Inoue,Sasaki
p. 1931 - 1938
(2007/10/02)

A facile conversion of the phenylthio group to acetoxy by copper reagents for a practical synthesis of 4-acetoxyazetidin-2-one derivatives from (R)-butane-1,3-diol
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Nakatsuka,Iwata,Tanaka,Imajo,Ishiguro
p. 662 - 664
(2007/10/02)

A NOVEL SUBSTITUTION REACTION OF 4-SULFINYLAZETIDIN-2-ONE WITH SILYLATED HETERONUCLEOPHILES: AN EFFICIENT SYNTHESIS OF 4-HETEROFUNCTION SUBSTITUTED 3-(1-HYDROXY)ETHYLAZETIDIN-2-ONES
4-Sulfinylazetidin-2-one was reacted with silylated heteronucleophiles in the presence of a catalytic amount of zinc iodide to give the corresponding trans-4-heterofunction substituted azetidin-2-ones in high yields.
Kita, Yasuyuki,Shibata, Norio,Yoshida, Naoki,Tohjo, Takashi
p. 2375 - 2378
(2007/10/02)

Ruthenium-Catalyzed Oxidation of Amides and Lactams with Peroxides
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Murahashi, Shun-Ichi,Naota, Takeshi,Kuwabara, Toshiyuki,Saito, Takao,Kumobayashi, Hidenori,Akutagawa, Susumu
p. 7820 - 7822
(2007/10/02)

Novel syntheses of the carbapenem key intermediates, (3R,4R)-4-acetoxy 3-[(R)-1-(t-butyldimethylsilyloxy)ethyl]-2-azetidinone and (3S,4R)-3-[(R)-1-(t-butyldimethylsilyloxy)ethyl]-4-carboxymethyl-2- azetidinone, from (S)-ethyl lactate
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Ito,Kobayashi,Kawabata,Takase,Terashima
p. 5767 - 5790
(2007/10/02)

Azetidinone derivatives and processes for production thereof
The invention relates to a method of producing an azetidinone derivative of the formula: STR1 which comprises reacting a compound of the formula STR2 with a compound of the formula STR3 and then subjecting the resulting compound to hydrolysis, the substituents above being as defined in the specification.
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(2008/06/13)

NEW SYNTHESIS OF 4-ACETOXY-2-AZETIDINONES BY USE OF ELECTROCHEMICAL OXIDATION
Optically pure 4-acetoxy-3--2-azetidinone(1b), which is a highly versatile intermediate for the synthesis of thienamycin(2) and other biologically active β-lactam analogs, was synthesized from 4-carboxy-3--2-azetidinone(18) by Kolbe-type electrolysis.
Mori, Miwako,Kagechika, Katsuji,Tohjima, Koh,Shibasaki, Masakatsu
p. 1409 - 1412
(2007/10/02)

CHIRAL SYNTHESIS OF 3--4-OXOAZETIDIN-2-YL ACETATE USING AN ASYMMETRIC 1,3-DIPOLAR CYCLOADDITION REACTION
3--4-oxoazetidin-2-yl acetate (4; R = H), a key intermediate for the preparation of penem and carbapenem antibiotics was synthesized in an optically active form using a 1,3-dipolar cycloaddition reaction of a chiral nitrone (6) as a key step.
Kametani, Tetsuji,Chu, Shih-Der,Honda, Toshio
p. 1593 - 1598
(2007/10/02)

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
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.
p. 1129 - 1135
(2007/10/02)

Anhydropenicillin: A key intermediate for the stereocontrolled introduction of the 6-R-hydroxyethyl side chain of the penem and carbapenem antibiotics
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Martel,Daris,Bachand,Menard
p. 2179 - 2181
(2007/10/02)

PRACTICAL SYNTHESIS OF (3R,4R)-4-ACETOXY-3-AZETIDIN-2-ONE. A KEY INTERMEDIATE FOR PENEM AND CARBAPENEM SYNTHESIS.
The title compound 5 was conveniently synthesized from anhydropenicillin 1 without isolating intermediates in an overall yield of 52percent.
Endo, Masaki
p. 1029 - 1034
(2007/10/02)

CHEMISTRY OF PENICILLIN DIAZOKETONES. PART II: FROM BETA-LACTAM TO BETA-LACTONE
Carbenes formed by transition metal catalyzed decomposition of penicillin-derived diazoketones can undergo different reaction pathways, depending on the presence or absence of the gem-dimethyl group.In the presence of the gem-dimethyl group products are formed via a sulfur ylide intermediate.Bis-nor derivatives undergo Wolff-rearrangement into ketenes which react further to give isopenams.If an hydroxyethyl substituent is present at C-6 of the starting material the original β-lactam is converted into a β-lactone.
Ludescher, Hans,Mak, Ching-Pong,Schulz, Gerhard,Fliri, Hans
p. 885 - 894
(2007/10/02)

ASYMMETRIC SYNTHESIS OF 4-ACETOXY-3HYDROXYETHYLAZETIDIN-2-ONE, A KEY INTERMEDIATE FOR THE PREPARATION OF PENEM AND CARBAPENEM ANTIBIOTICS
Asymmetric synthesis of 4-acetoxy-3-hydroxyethylazetidin-2-one with desired stereochemistry has been achieved by employing dipolar cycloaddition of a chiral nitrone with benzyl crotonate as a key reaction.
Kametani, Tetsui,Chu, Shih-Der,Honda, Toshio
p. 241 - 244
(2007/10/02)

From penicillin to penem and carbapenem. VII. Synthesis and antibacterial activity of penem derivatives
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Fujimoto,Iwano,Hirai,Sugawara
p. 999 - 1014
(2007/10/02)

A NOVEL SYNTHESIS OF (3R,4R)-4-ACETOXY-3--2-AZETIDINONE, THE VERSATILE KEY INTERMEDIATE OF CARBAPENEM SYNTHESIS, FROM (S)-ETHYL LACTATE
A highly efficient synthesis of the title compound was accomplished employing the addition of diketene to chiral imine as a key stereoselective reaction and using inexpensive (S)-ethyl lactate as a starting material.
Ito, Yoshio,Kawabata, Takeo,Terashima, Shiro
p. 5751 - 5754
(2007/10/02)

A SYNTHETIC APPROACH TO (+)-THIENAMYCIN FROM METHYL (R)-3-HYDROXYBUTANOATE. A NEW ENTRY TO (3R, 4R)-3--4-ACETOXY-2-AZETIDINONE
A new entry to the O-silylated form of the title azetidinone, a well-established key intermediate for thienamycin synthesis, is described which relies on the stereocontrolled transformation of the 2-azetidinone obtained via the condensation of methyl (R)-3-hydroxybutanoate with the N-silylimine of trimethylsilylpropynal.
Chiba, Toshiyuki,Nakai, Takeshi
p. 651 - 654
(2007/10/02)

AN IMPROVED ENTRY TO A KEY INTERMEDIATE FOR THIENAMYCIN SYNTHESIS FROM METHYL (R)-3-HYDROXYBUTANOATE VIA DIRECT EPIMERIZATION AT C-3 ON 2-AZETIDINONE RINGS
An improved entry to a key thienamycin intermediate is described which relies upon the direct epimerization at C-3 of the 3-(1-hydroxyethyl)-2-azetidinone derivatives readily obtained from methyl (R)-3-hydroxybutanoate.
Chiba, Toshiyuki,Nakai, Takeshi
p. 4647 - 4648
(2007/10/02)