ChemInform Abstract: Thermal Rearrangement of 2,5-Bis(allyloxy)tropone, Revisited. Formation of Four Thermolysates Under the Claisen Rearrangement Conditions and Structure Revision of the Major Thermolysate.

ChemInform ◽  
1987 ◽  
Vol 18 (40) ◽  
Author(s):  
H. TAKESHITA ◽  
A. MORI ◽  
Y. GOTO ◽  
T. NAGAO
Keyword(s):  
Claisen Rearrangement ◽  
Thermal Rearrangement ◽  
Structure Revision

HALOGEN MIGRATION AND ELIMINATION IN THE CLAISEN REARRANGEMENT OF ALLYL 2,6-DIHALOPHENYL ETHERS

1963 ◽  
Vol 41 (12) ◽  
pp. 2917-2930 ◽  
Author(s):  
E. Piers ◽  
R. K. Brown
Keyword(s):  
Dielectric Constant ◽  
Lewis Acids ◽  
Claisen Rearrangement ◽  
Stannous Chloride ◽  
Ionic Species ◽  
Thermal Rearrangement ◽  
Polar Solvents ◽  
Factors Affecting ◽  
Competitive Reduction ◽  
Catalytic Effects

A study has been made of some factors affecting the migration or elimination of halogen in the Claisen rearrangement of allyl 2,6-dihalophenyl ethers.In the thermal rearrangement of allyl 2,6-dichlorophenyl ether, carried out in a number of solvents of different dielectric constant, halogen migration proceeds somewhat better in highly polar solvents. However, a competitive reduction to the monohalogenated allylphenol occurs in the presence of oxidizable solvents and/or products. The reaction is also complicated by the catalytic effects of certain solvents and the phenolic products, which give results similar to those obtained with Lewis acids. Stannous chloride acts as a Lewis acid and catalyzes the rearrangement of allyl 2,6-dichlorophenyl ether with simultaneous halogen rearrangement. As well, a competitive reductive removal of the halogen takes place. Results from the rearrangement of allyl 2,6-dibromophenyl ether with zinc chloride and of allyl 2,6-dichlorophenyl ether with zinc bromide, as well as those from the stannous chloride reactions indicate that the halogen migration takes place not only by an allylic shift but also via a competitive halogen substitution probably occurring by an Sn2′ pathway possibly assisted by a zinc halide bridge mechanism and/or an ionic species such as [Formula: see text].

THE AMIDE-CLAISEN REARRANGEMENT. III. THE THERMAL REARRANGEMENT OFN-ALLYL-N-TOSYLANILINE

1973 ◽  
Vol 2 (11) ◽  
pp. 1213-1216 ◽  
Author(s):  
Seisaku Inada ◽  
Syuhei Ikado ◽  
Mitsuo Okazaki
Keyword(s):  
Claisen Rearrangement ◽  
Thermal Rearrangement
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