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Darstellung und Photochemie eines (Anthrylvinyl)thiophenfulgids
Author(s) -
Effenberger Franz,
Wonner Johann
Publication year - 1992
Publication title -
chemische berichte
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 0009-2940
DOI - 10.1002/cber.19921251133
Subject(s) - chemistry , wittig reaction , thiophene , tautomer , condensation , phosphonium , medicinal chemistry , valence (chemistry) , intramolecular force , ylide , base (topology) , photochemistry , polymer chemistry , organic chemistry , mathematical analysis , physics , mathematics , thermodynamics
Preparation and Photochemistry of an Anthrylvinyl Thiophene Fulgide The base‐catalyzed reaction of isopropylidenesuccinate 2 with phenylthienylpropenone 1a does not give a Stobbe condensation to 3a but results in an 1,4‐addition to 7 which under the basic conditions reacts further to 8 by an intramolecular condensation. The (anthrylvinyl)thiophene fulgide 4c is obtained, however, from 3‐glyoxyloyl‐2,5‐dimethylthiophene hydrate ( 11 ) via the 2 H ‐pyran 14 : Wittig olefination of 14 with the phosphonium salt 16 leads to the diester 3c which easily is converted to Z,E ‐ 4c . – Irradiation of Z,E ‐ 4c gives a mixture of all four possible E,Z isomers of 4c and the ring‐closed valence tautomers Z ‐ and E ‐ 17 . All isomers could be separated and characterized. Compound 18 , formed irreversibly in a thermally‐induced reaction, is enriched during irradiation.