synthesized by ring closing metathesis (RCM) of sulfonates. The resulting α,β-unsaturated sultones act as dienophiles in intermolecular Diels-Alder reactions. A first cyclic sulfate formation throughRCM has been discovered, and a rapid access to p-lactams fused to a sultam moiety of variable ring size was developed from inexpensive, commercially available starting materials using RCM as the key operation
New approaches to the synthesis of β-lactam antibiotics
作者:John Knight、Philip J. Parsons、Robert Southgate
DOI:10.1039/c39860000078
日期:——
New synthesis of carbapenams and carbacephams are presented using radical cyclisation techniques.
介绍了利用自由基环化技术合成碳青霉烯类和碳青霉烯类的新方法。
A concise synthesis of β-lactam–sulfonamide hybrids
作者:Dirk Freitag、Pia Schwab、Peter Metz
DOI:10.1016/j.tetlet.2004.03.055
日期:2004.4
Using ring closing metathesis (RCM) as the key operation, a rapid access to beta-lactams fused to a sultam moiety of variable ring size was developed from low cost, commercially available starting materials. An efficient RCM of 4-vinyl-azetidin-2ones to give I-aza-bicyclo[4.2.0]oct-4-en-8-ones is also reported. (C) 2004 Elsevier Ltd. All rights reserved.
Rapid Entry into Mono-, Bi-, and Tricyclic β-Lactam Arrays via Alkene Metathesis
作者:Anthony G. M. Barrett、Simon P. D. Baugh、D. Christopher Braddock、Kevin Flack、Vernon C. Gibson、Matthew R. Giles、Edward L. Marshall、Panayiotis A. Procopiou、Andrew J. P. White、David J. Williams
DOI:10.1021/jo981150j
日期:1998.10.1
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 beta-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 beta-lactam alkenes with styrene partners and ring closing metathesis of beta-lactam dienes using the Schrock [(CF3)(2)MeCO](2)Mo(=CHCMe2Ph)(=NC6H3-2,6-iso-Pr-2) (1) or Grubbs Cl-2(Cy3P)(2)Ru=CHPh (2) carbenes gave diverse monocyclic and bicyclic beta-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 beta-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).
KNIGHT, JOHN;PARSONS, PHILIP J., J. CHEM. SOC. PERKIN TRANS., 1,(1987) N 6, 1237-1242