ISSN:
1434-193X
Keywords:
(E,E)-2′-Hydroxycinnamylideneacetophenones
;
(E)- and (Z)-2-Styrylchromones
;
Xanthones
;
Oxidative cyclizations
;
Configuration determination
;
Chemistry
;
General Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
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 12H-benzo[a]xanthene-12-ones 6a,f-h.
Type of Medium:
Electronic Resource
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