scholarly journals α-Selective Glycosylation with β-Glycosyl Sulfonium Ions Prepared via Intramolecular Alkylation

2019 ◽  
Vol 84 (7) ◽  
pp. 4486-4500 ◽  
Author(s):  
Sam J. Moons ◽  
Rens A. Mensink ◽  
Jeroen P. J. Bruekers ◽  
Maurits L. A. Vercammen ◽  
Laura M. Jansen ◽  
...  
Keyword(s):  
Intramolecular Alkylation ◽  
Sulfonium Ions

Cyclization of 2-(2-bromoethoxy)-acetophenones and 5-(ω-haloalkoxy)-1,5-dihydro-2H-pyrrol-2-ones – Formation of five- to eight-membered oxygen-containing heterocycles via intramolecular alkylation

2004 ◽  
Vol 82 (5) ◽  
pp. 571-578 ◽  
Author(s):  
Kirill V Nikitin ◽  
Nonna P Andryukhova
Keyword(s):  
Sodium Hydride ◽  
Spiro Compounds ◽  
Lithium Diisopropylamide ◽  
Intramolecular Alkylation ◽  
High Yields

Under basic conditions (lithium diisopropylamide or sodium hydride in THF) 2-(2-bromoethoxy)-acetophenones were transformed to 3,4-dihydro[1]benzoxepin-5(2H)-ones (homochromanones) in high yields. The preparation of novel tetrahydropyrano[2,3-b]pyrrol-6(2H)-ones and 3,4-dihydro-2H-pyrrolo[2,1-b][1,3]oxazin-6(8aH)-ones and spiro compounds was performed using similar cyclization in moderate to good yields.Key words: cyclization, lithiation, spiro heterocycles.

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.

Synthesis of β-Lactams via Intramolecular Alkylation

1971 ◽  
Vol 1 (1) ◽  
pp. 51-73 ◽  
Author(s):  
Ajay K. Bose ◽  
M. S. Manhas ◽  
B. G. Chatterjce ◽  
R. F. Abdulla
Keyword(s):  
Intramolecular Alkylation
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