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Novel ( E )‐ and ( Z )‐2‐Styrylchromones from ( E, E )‐2′‐Hydroxycinnamylideneacetophenones – Xanthones from Daylight Photooxidative Cyclization of ( E )‐2‐Styrylchromones
Author(s) -
S. Silva Artur M.,
Pinto Diana C. G. A.,
Tavares Hilário R.,
Cavaleiro José A. S.,
Jimeno M. Luisa,
Elguero José
Publication year - 1998
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/(sici)1099-0690(199809)1998:9<2031::aid-ejoc2031>3.0.co;2-#
Subject(s) - chemistry , stereochemistry , xanthene , medicinal chemistry , photochemistry
The oxidative cyclization of ( E , E )‐2′‐hydroxycinnamylideneacetophenones 1a–e , and ( E, E )‐2′‐benzyloxy‐6′‐hydroxycinnamylideneacetophenones 1i–l with DMSO/iodine, gave ( E )‐2‐styrylchromones 3a–e , i–l . However, in the case of ( E, E )‐γ‐alkyl‐2′‐hydroxycinnamylideneacetophenones 1f–h , ( E )‐ and ( Z )‐2‐styrylchromones 3f–h and 4f–h were obtained. The stereochemistry of the ( E , E )‐cinnamylideneacetophenones 1 and ( E )‐ and ( Z )‐2‐styrylchromones 3 and 4 was established by NOE experiments. The induced daylight photooxidative cyclization of some ( E )‐2‐styrylchromones 3a , f–h gave 12 H ‐benzo[ a ]xanthene‐12‐ones 6a , f–h .