ISSN:
0018-019X
Schlagwort(e):
Chemistry
;
Organic Chemistry
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
Notizen:
The base-catalyzed reaction of 4-nitro-3-oxobutyrate (6) with acetylacetone (8 Scheme 3), formylacetone (13, Scheme 4), formylcyclohexanone (31, Scheme 5), 2,4-dioxopentanoates 39 and 40 (Scheme 6), and 2,4,6-heptanetrione (2, Scheme 7) affords substituted 3-nitrosalicylates, products of a double aldol condensation. With unsymmetrical dicarbonyl compounds both regioisomers are formed. High selectivity was found in the case of β-keto-aldehydes 13 and 31 with preferred addition of the NO2-substituted carbon to the aldehyde carbonyl. The major products of these cyclocon-densations, which are isolated in yields ranging from 20% to 80%, are all new compounds. Less successful are the conversions with β-alkoxy- and β-chloro-vinyl ketones (23, 25, and 26), and with alkinone 24, where the condensation products are formed in very low yield (Scheme 4).
Zusätzliches Material:
1 Tab.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/hlca.19830660821