Premium
The reactions of 4‐hydroxy‐2‐pyrones with 2‐hydroxybenzaldehydes. A note of warning
Author(s) -
De March P.,
MorenoMañas M.,
Roca J. L.
Publication year - 1984
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.5570210525
Subject(s) - chemistry , molar ratio , pyran , pyrone , lactone , stereochemistry , medicinal chemistry , organic chemistry , catalysis
Abstract The reaction between 2‐hydroxybenzaldehyde and 4‐hydroxy‐6‐methyl‐2‐pyrone (triacetic acid lactone) affords 3‐acetoacetyl‐2‐chromenone, 7 , instead of 3‐(2‐hydroxybenzylidene)‐6‐methyl‐3,4‐dihydro‐2 H ‐pyran‐2,4‐dione, 6 . The structures previously reported in the literature for the products formed in the reactions of 4‐hydroxy‐2‐chromenone with 2‐hydroxybenzaldehydes in a molar ratio 1:1 are considered erroneous. Thus, the previously reported 3‐(2‐hydroxybenzylidene)chroman‐2,4‐dione, 10 , should be formulated as 3‐(2‐hydroxybenzoyl)‐2‐chromenone, 11 .