68485-52-9Relevant articles and documents
A New Method for the Carbon-extension Reactions of Azetidin-2-ones at the 4-Position
Kobayashi, Takeo,Ishida, Nobory,Hiraoka, Tetsuo
, p. 736 - 737 (1980)
High yields of 4-alkyl-, 4-allyl-, 4-vinyl-, or 4-ethynynl-azetidin-2-ones are obtained by treating 4-sulphonylazetidin-2-ones with either lithium organocuprates or Grignard reagents, but yields from 4-acetoxyazetidin-2-one with Grignard reagents are low.
Ring-closing metathesis of vinyl fluorides towards α-fluorinated α,β-unsaturated lactams and lactones
Marhold, Michael,Stillig, Christian,Fr?hlich, Roland,Haufe, Günter
supporting information, p. 5777 - 5785 (2014/10/15)
Ring-closing olefin metathesis reactions (RCM) using Grubbs II or Hoveyda's catalysts have been applied to a series of N-alkenyl-N-benzyl-α-fluoroacrylamides. α-Fluoro-α,β-unsaturated γ- or δ-lactams incorporating a fluorinated double bond were obtained in moderate to good yields, depending on the nature of substituents on the benzyl ring. The corresponding seven- and eight-membered lactams were not formed under similar conditions. When the N-benzyl group was replaced by an N-tosyl group, the corresponding ε-lactam was also formed in 38% yield. When N-(2-fluoroallyl) derivatives were used instead of fluoroacryloyl derivatives, six-, seven-, and eight-membered N-heterocycles were obtained in low yields. This method was also used to synthesize fluorinated α,β-unsaturated analogues of pyrrolizidine and indolizidine alkaloids from prolinol, and also to synthesize N-benzyl-3-fluoroquinolone in three steps from commercially available 2-vinylaniline in 44% overall yield. Also 3-fluorocoumarin and 3-fluorochromene were prepared from ovinylphenol, and 3-fluoro-benzoxepine was available from o-allylphenol.
Rapid entry into mono-, bi-, and tricyclic β-lactam arrays via alkene metathesis
Barrett, Anthony G. M.,Baugh, Simon P. D.,Christopher Braddock,Flack, Kevin,Gibson, Vernon C.,Giles, Matthew R.,Marshall, Edward L.,Procopiou, Panayiotis A.,White, Andrew J. P.,Williams, David J.
, p. 7893 - 7907 (2007/10/03)
4-Acetoxy-2-azetidinone and (3R,4R)-4-acetoxy-3-[(1R)-1-(tert- butyldimethylsilyl)-oxyethyl]-2-azetidinone were converted into 4-alkenyloxy- , 4-(N-allyltoluene-4-sulfonamido)-, 4-(allylthio)-, and 4-alkenyl-2- azetidinone systems. In addition, 4-acetoxy-2-azetidinone and (3R,4R)-4- acetoxy-3-[(1R)-1-(tert-butyldimethylsilyl)-oxyethyl]-2-azetidinone were converted into β-lactam dienes via sequential C-4 substitution using unsaturated alcohols, allyl mercaptan, N-allyltoluene-4-sulfonamide, and allyl(chloro)dimethylsilane followed by N-allylation. Crossed metathesis of β-lactam alkenes with styrene partners and ring closing metathesis of β- lactam dienes using the Schrock [(CF3)2MeCO]2Mo(=CHCMe2Ph)(=NC6H3-2,6- iso-Pr2) (1) or Grubbs Cl2(Cy3P)2Ru=CHPh (2) carbenes gave diverse monocyclic and bicyclic β-lactam systems including derivatives of 1- azabicyclo-[4.2.0]octan-8-one, 1-azabicyclo[5.2.0]nonan-9-one and its 6- thia, 6-aza, and 6-oxa analogues, 7-oxa-1-azabicyclo[6.2.0]octan-10-one,8- oxa-1-azabicyclo[7.2.0]octan-11-one, and 9-oxa-1-azabicyclo[8.2.0]octan-12- one. Ring-closing enyne metathesis and tandem ring-closing enyne and diene metathetic reactions were used to produce bicyclic β-lactam conjugated dienes as exemplified by the conversion of (3S,4R)-(-)-3-[(1R)-(tert- butyldimethylsilyl)oxyethyl]-1-(5-oxa-oct-7-en-2-yn-1-yl)-4-(2-propenyl)- azetidin-2-one (83) into (6R,7S)-(+)-7-[(1R)-(tert- butyldimethylsilyl)oxyethyl]-3-[(2,5-dihydro)-3-furanyl]-1- azabicyclo[4.2.0]oct-3-en-8-one (98).
A new access to racemic carbacephems
Oumoch, Said,Rousseau, Gerard
, p. 997 - 1003 (2007/10/03)
A new approach to carbaccphems is reported involving the formation of the six-membered ring by cyclization of N-acyliminium ions. With methylene iminium species the reaction appeared general, while with (methoxycarbonyl)methylene iminium intermediates the
