28562-53-0Relevant articles and documents
A Superior Procedure for the Preparation of 2-Azetidinones From Volatile Olefins
Hauser, Frank M.,Ellenberger, Suzanne R.
, p. 324 (1987)
The use of a pressure bottle for cycloaddition of chlorosulfonyl isocyanate with volatile olefins not only provides the azetidinones in significantly improved yield, but also greatly simplifies the experimental procedure.
Studies on the design and synthesis of new monocyclic β-lactams containing substructures of penicillin G
Lee, Sang Hyup
, p. 2990 - 2994 (2014/12/10)
The studies on design and synthesis of new monocyclic β-lactam esters 4(R/S)-(1′-methoxycarbonylpropyl-2′(R/S)-thio)-3(R)-phenylacetamidoazetidin-2-one (3a) and 4(R/S)-(1′-methoxycarbonyl-2′-methyl-propyl-2′-thio)-3(R)-phenylacetamidoazetidin-2-one (3b) were described. Compounds 3a and 3b were specifically designed to retain all penicillin substructures except the bicyclic system, which would be conceived by cleaving the C(3)-N(4) bond of penicillin G. Compounds 3a and 3b are of particular interest in the context of the structural elucidation of monocyclic β-lactams originated from penicillin. Key intermediates, β-mercapto esters 6a and 6b, were synthesized from conjugate acids 4a and 4b using three-step synthetic sequences, respectively, and 4(S)-acetoxy-3(S)-phenylacetamidoazetidin-2-one (7) was obtained from the degradation of penicillin G. Reactions of 6a and 6b with 7, thus obtained, provided the target compounds 3a and 3b, respectively.
N-acyl-β-lactam derivative, macromolecular compound, and photoresist composition
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Paragraph 0258-0261, (2014/10/28)
Provided are N-acyl-β-lactam derivatives represented by the following general formula, from which a photoresist composition capable of controlling an acid diffusion length to be short is obtained; a polymer obtained by polymerizing the N-acyl-β-lactam derivative represented by the following general formula as one of starting materials; and a photoresist composition containing the polymer, where the structural variables are as defined herein.
Design and synthesis of new 4-alkylthio monocyclic β-lactams
Lee, Sang Hyup
, p. 121 - 127 (2013/08/24)
New types of monocyclic β-lactams constitute an important class of compounds due to their unique structures and natures. Here, the design and synthesis of new 4-alkylthio monocyclic β-lactams 2a and 3a are reported. Significantly, compounds 2a and 3a, while keeping a monocyclic system, were designed to contain all of the substructures provided by the cleavage of C(2)-C(3) bond in penicillins. Efficient synthetic pathways for compounds 2a and 3a were established based on two different strategies. Compound 2a was synthesized from raw materials, using 4-acetoxyazetidin-2-one as a key intermediate, through a ten-step synthetic sequence in 3% overall yield. Compound 3a was synthesized from potassium salt of penicillin G (17), using the degraded product 20 as a key intermediate, through a six-step synthetic sequence in 11% overall yield. 4-Alkylthioazetidin- 2-one derivatives, introduced in this study, could serve as valuable intermediates for the development of new monocyclic β-lactams.
Convergent synthesis of (2R,3R,8R,9R)-N-Boc-ADDA
Meiries, Sebastien,Marquez, Rodolfo
, p. 5015 - 5021 (2008/12/20)
(Figure Presented) The convergent synthesis of N-Boc-(2R,3R,8R,9R,4E,6E)-3- amino-9-methoxy-2,6,8-trimethyl-10-phenyldecadenoic acid (enantio-N-Boc-ADDA) is reported. Our flexible approach takes advantage of highly efficient non-aldol aldol and cross-metathesis methodologies.
Stereocontrolled synthesis of 1-oxacepham from 4-vinyloxyazetidin-2-one, a new building block
Kaluza, Zbigniew,Lysek, Robert
, p. 2553 - 2560 (2007/10/03)
A new methodology for 1-oxacepham synthesis is described. Readily available 4-vinyloxyazetidin-2-one 2 is shown to be a useful building block for β-lactam synthesis. N-Alkylation of 2 is followed by oxidation of the vinyloxy group to give 4-acyloxy-N-substituted azetidin-2-ones suitable for nucleophilic displacement at the C-4 carbon atom. The ring closure reaction offers high stereoselectivity.
Substituted acetoxyazetidinone derivatives and process for preparing 4-acyloxyazetidinone derivatives
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, (2008/06/13)
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.
Ruthenium catalyzed process for preparing 4-acetoxyazetidinones
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, (2008/06/13)
A simplified process for preparing 4-acetoxyazetidinones of formula (I): STR1 wherein Z is a hydrogen atom, a lower alkyl group or a hydroxyethyl group which may or may not be protected is disclosed. According to the invention, azetidinones of formula (II): STR2 wherein Z has the same meaning as defined above and Y is a hydrogen atom or a carboxyl group is reacted with acetic acid and an oxidizing agent in the presence of a ruthenium compound represented by the formula [Ru(B)2 (L)]m wherein B is Cl, Br or l, m is a positive integer, and L is 1,5-cyclooctadiene, norbornadiene, cycloheptatriene, cyclooctatetraene or benzene which may or may not have a lower alkyl group as a substituent, as a catalyst.
Synthesis of the Alkaloids Hopromine, Hoprominol and Hopromalinol, using Transamidation Methods
Crombie, Leslie,Haigh, David,Jones, Raymond C. F.,Mat-Zin, Ab. Rasid
, p. 2055 - 2068 (2007/10/02)
Synthesis of the unsymmetrical Homalium alkaloids hopromine, hoprominol and hopromalinol, in diastereoisomeric mixture form, is reported.The component eight-membered azalactams are first prepared.N-(3-Halogenopropyl)-4-pentyl- and -4-heptyl-azetidin-2-ones are aminated and ring expanded in liquid ammonia to give, after reductive methylation, the corresponding 4-alkyl-5-methyl-1,5-diazacyclooctan-2-ones.Synthesis of the 4-(2-hydroxyheptyl)-5-methyl-1,5-diazacyclooctan-2-one required for hoprominol and hopromalinol is carried out via 4-allyl β-lactam ring expansion to the eight-membered 4-allylazalactam, followed by methylation, epoxidation and epoxide opening with lithium dibutylcuprate.A similar epoxidation-cuprate sequence was carried out on the epoxypropyl β-lactam, as its N-tert-butyldimethylsilyl derivative, and led to a convenient copper-catalysed N- to O-migration of the protection; this migration is examined.Alkylation gave O-TBDMS-protected N-(3-chloropropyl)-4-(2-hydroxyheptyl)azetidin-2-one which could be aminated and transamidated in excellent yield, to give, after methylation, a superior sequence to the required eight-membered hydroxy azalactam.Although satisfactory for attachment of the first azalactam unit, a dibromobutane coupling system proved unreactive for the second.Couplings with unmethylated, methylated, and benzyloxycarbonyl-protected azalactams were examined using (E)-1,4-dibromobutene and (Z)-1,4-dichlorobutene as the bridging unit.Employing the latter, coupling the first N-methylated azalactam with potassium bis(trimethylsilyl)amide as the base, and then the second with bis(trimethylsilyl)amide-sodium hydride as the base system, provided a satisfactory synthetic outcome.Hydrogenation under acidic conditions gave the unsymmetrical structures hopromine, hoprominol and hopromalinol, as well as the more simple and symmetrical alkaloid, homaline.
Acetyloxylation process for producing 4-acetoxyazetidinones with osmium catalyst
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, (2008/06/13)
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.
