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Neue Umlagerungen von Aryl‐allyl‐äthern und Allylphenolen. (Vorläufige Mitteilung)
Author(s) -
Borgulya J.,
Hansen H.J.,
Barner R.,
Schmid H.
Publication year - 1963
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19630460664
Subject(s) - chemistry , steric effects , phenols , phenol , aryl , medicinal chemistry , yield (engineering) , stereochemistry , organic chemistry , alkyl , materials science , metallurgy
In position 3 (and 5) substituted phenyl‐γ‐methyl (and phenyl)‐allylethers when subjected to the thermal C LAISEN ‐rearrangement not only yield the expected o ‐allyl‐phenols but in addition considerable amounts of the P ‐allylated phenols. Migration to the para ‐position is favoured by non‐polar solvents. This para ‐migration of the substituted allylgroup is attributed mainly to steric factors. With sterically hindered, in ortho ‐ or para ‐position allylated phenols there was furthermore found an allyl‐phenol‐rearrangement: on sufficient heating to 200° these substances are transformed to the thermodynamically more stable para ‐ resp. ortho ‐allylphenols with inversion of the allyl group.