ChemInform Abstract: Lewis Acid Catalyzed α-Functionalization of Ketals for the Regioselective Synthesis of α-Carbamoyl Ketals.

ChemInform ◽  
2012 ◽  
Vol 43 (48) ◽  
pp. no-no
Author(s):  
Philip Magnus ◽  
Alec J. Brozell
Keyword(s):  
Lewis Acid ◽  
Regioselective Synthesis ◽  
Acid Catalyzed

Regioselective Synthesis of Maturone via Lewis Acid Catalyzed Deils-Alder Reaction

Heterocycles ◽  
1993 ◽  
Vol 35 (1) ◽  
pp. 33 ◽  
Author(s):  
Ken Kanematsu ◽  
Mariko Aso ◽  
Akio Ojida ◽  
Guang Yang
Keyword(s):  
Lewis Acid ◽  
Alder Reaction ◽  
Regioselective Synthesis ◽  
Acid Catalyzed

Regioselective synthesis of biologically interesting pentacyclic polyheterocycles by sequential thio-Claisen and AlCl3 catalyzed oxy-Claisen rearrangement of 4-(4′-aryloxybut-2′-ynylthio)-1-phenyl-1,8-naphthyridin-2(1H)-one

2006 ◽  
Vol 84 (12) ◽  
pp. 1632-1639 ◽  
Author(s):  
K C Majumdar ◽  
R Islam
Keyword(s):  
Lewis Acid ◽  
Claisen Rearrangement ◽  
Phase Transfer Catalysis ◽  
Phase Transfer ◽  
Acid Catalyst ◽  
Sigmatropic Rearrangement ◽  
Regioselective Synthesis ◽  
X Ray ◽  
Lewis Acid Catalyst ◽  
Acid Catalyzed

A number of 4-aryloxymethyl-6-phenyl-2H-thiopyrano[3,2-c][1,8]naphthyridin-5(6H)-ones were regio selectively synthesized in 82%–95% yields by the thermal Claisen rearrangement of 4-(4′-aryloxybut-2′-ynylthio)-1-phenyl-[1,8]naphthyridin-2(1H)-ones. These products were then subjected to a second Claisen rearrangement in the presence of a Lewis acid catalyst, anhyd. AlCl3, to give hitherto unreported pentacyclic heterocycles in 75%–90% yields. The same final products were also obtained in low yield upon refluxing 4-aryloxymethyl-6-phenyl-2H-thio pyrano-[3,2-c][1,8]naphthyridin-5(6H)-ones in N,N-diethyl aniline for 12–14 h. This method was found to be more effective than thermal Claisen rearrangement.Key words: [3,3] sigmatropic rearrangement, regioselective synthesis, phase transfer catalysis, sequential Claisen rearrangement, Lewis acid catalyzed Claisen rearrangement, single crystal X-ray.

Lewis acid catalyzed Claisen rearrangement: Regioselective synthesis of oxygen, nitrogen, and sulfur heterocycles

2008 ◽  
Vol 86 (1) ◽  
pp. 72-78 ◽  
Author(s):  
K C Majumdar ◽  
A K Pal
Keyword(s):  
Lewis Acid ◽  
Claisen Rearrangement ◽  
Sigmatropic Rearrangement ◽  
Regioselective Synthesis ◽  
Aluminium Chloride ◽  
Sulfur Heterocycles ◽  
Acid Catalyzed

Regioselective synthesis of pentacyclic heterocycles containing oxygen, nitrogen, and sulfur has been achieved in good to excellent yields by the sequential Claisen rearrangement of but-2-ynyl ethers and sulfides containing quinolone moiety. The substrates ethers and sulfides were prepared from 1-aryloxy-4-chlorobut-2-ynes with N-alkyl-4-hydroxyquinoline-2(1H)-ones.Key words: regioselectivity, [3,3] sigmatropic rearrangement, nucleophilicity of sulfur, aluminium chloride, heterocycles.

Sign in / Sign up

Export Citation Format

Share Document