Generic synthesis of β-sultams via domino alkylation of bromomethanesulfonamides

2004 ◽  
Vol 82 (2) ◽  
pp. 113-119 ◽  
Author(s):  
William R Barton ◽  
Leo A Paquette
Keyword(s):  
Functional Groups ◽  
Potassium Carbonate ◽  
Membered Ring ◽  
Ring Closing Metathesis ◽  
Intramolecular Alkylation ◽  
Ketone Ester

Reaction of N-substituted bromomethanesulfonamides with 2 equiv of potassium carbonate and an α-halo ketone, ester, or nitrile leads directly to 3-substituted β-sultams. The first step is intermolecular and is followed by an intramolecular alkylation. The process is particularly efficient when diethyl bromomalonate and 3-chloro-2-butanone are involved. In the latter example, no competitive cyclization to form a six-membered ring is seen. The functional groups in certain of the β-sultam products can be subsequently manipulated to give bicyclic products.Key words: β-sultams, intramolecular SN2 displacement, sulfonamides, ring closing metathesis, four-membered heterocycles.

Concise synthesis of five-membered ring carbasugars based on key ring-closing metathesis

2010 ◽  
Vol 51 (29) ◽  
pp. 3848-3851 ◽  
Author(s):  
Ya-Xi Yang ◽  
Zheng Li ◽  
Hui-Jin Feng ◽  
Guo-Rong Chen ◽  
Yuan-Chao Li
Keyword(s):  
Membered Ring ◽  
Ring Closing Metathesis

Synthesis of the C7-C17 Segment of Epothilones by a 10-membered Ring Closing Metathesis Reaction

Synlett ◽  
1998 ◽  
Vol 1998 (10) ◽  
pp. 1108-1110 ◽  
Author(s):  
Kai Gerlach ◽  
Monika Quitschalle ◽  
Markus Kalesse
Keyword(s):  
Membered Ring ◽  
Metathesis Reaction ◽  
Ring Closing Metathesis

Towards the Total Synthesis of Schisandrene: Stereoselective Synthesis of the Dibenzocyclooctadiene Lignan Core

Synlett ◽  
2018 ◽  
Vol 29 (07) ◽  
pp. 908-911 ◽  
Author(s):  
K. Babu ◽  
Arramshetti Venkanna ◽  
Borra Poornima ◽  
Bandi Siva ◽  
B. Babu
Keyword(s):  
Total Synthesis ◽  
Stereoselective Synthesis ◽  
Asymmetric Reduction ◽  
Cross Coupling ◽  
Membered Ring ◽  
Stille Reaction ◽  
Reaction Sequence ◽  
Ring Closing Metathesis ◽  
Synthetic Strategy ◽  
First Time

A stereoselective synthesis of the dibenzocyclooctadiene ­lignan core of the natural product schisandrene is described. Starting from readily available gallic acid, the synthetic strategy involves Suzuki–Miyaura cross-coupling, Stille reaction, and ring-closing metathesis (RCM) in the reaction sequence. The required asymmetric center at C-7′ was established by an asymmetric reduction of a keto compound using the Corey–Bakshi–Shibata (CBS) catalyst. In our approach, the eight-membered ring was achieved by RCM for the first time.

New functionalized poly(arylene-ether ketone)s and their use as modifiers for bismaleimide resin

1993 ◽  
Vol 5 (2) ◽  
pp. 123-137 ◽  
Author(s):  
H D Stenzenberger ◽  
P König
Keyword(s):  
Bisphenol A ◽  
Functional Groups ◽  
Potassium Carbonate ◽  
Displacement Reaction ◽  
Polymer Backbone ◽  
Bismaleimide Resin ◽  
Arylene Ether ◽  
Ether Ketone ◽  
Group Concentration

A series of new functionalized poly(arylene-ether ketone) copolymers has been prepared by the nucleophilic aromatic displacement reaction from 4,4'-difluorobenzophenone and mixtures of bisphenol-A and 2,2'-bis(3-allyl,4-hydroxyphenyl)-hexat Luoropropane (6F-DABA) in the presence of potassium carbonate. The propenyl functional groups are statistically distributed along the polymer backbone and their concentration was tailored by adjusting the concentration of the starting monomers. These functionalized poly(aryleneether ketone)s (FPAEK) were used as thermoplastic modifiers for a bismaleimide (BMI) resin. The influence of the propenyl group concentration on the toughness of BMI,'FPAEK blend systems was studied.

scholarly journals Bidirectional cross metathesis and ring-closing metathesis/ring opening of a C 2-symmetric building block: a strategy for the synthesis of decanolide natural products

2013 ◽  
Vol 9 ◽  
pp. 2544-2555 ◽  
Author(s):  
Bernd Schmidt ◽  
Oliver Kunz
Keyword(s):  
Building Block ◽  
Ring Opening ◽  
Kinetic Resolution ◽  
Membered Ring ◽  
Ring Closure ◽  
Ring Closing Metathesis ◽  
Cross Metathesis ◽  
Key Steps ◽  
A Site ◽  
Site Selective

Starting from the conveniently available ex-chiral pool building block (R,R)-hexa-1,5-diene-3,4-diol, the ten-membered ring lactones stagonolide E and curvulide A were synthesized using a bidirectional olefin-metathesis functionalization of the terminal double bonds. Key steps are (i) a site-selective cross metathesis, (ii) a highly diastereoselective extended tethered RCM to furnish a (Z,E)-configured dienyl carboxylic acid and (iii) a Ru–lipase-catalyzed dynamic kinetic resolution to establish the desired configuration at C9. Ring closure was accomplished by macrolactonization. Curvulide A was synthesized from stagonolide E through Sharpless epoxidation.

ChemInform Abstract: Synthesis of a Natural Product-Inspired Eight-Membered Ring Lactam Library via Ring-Closing Metathesis.

ChemInform ◽  
2009 ◽  
Vol 40 (3) ◽  
Author(s):  
Neil Brown ◽  
Baohan Xie ◽  
Nataliya Markina ◽  
David VanderVelde ◽  
Jean-Pierre H. Perchellet ◽  
...  
Keyword(s):  
Natural Product ◽  
Membered Ring ◽  
Ring Closing Metathesis
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