Reactions of 3-(polyfluoroacyl)chromones with hydroxylamine: synthesis of novel R(F)-containing isoxazole and chromone derivatives / Sosnovskikh Vyacheslav Ya.,Moshkin Vladimir S.,Kodess Mikhail I. // TETRAHEDRON. - 2008. - V. 64, l. 34. - P. 7877-7889.

ISSN/EISSN:

0040-4020 / нет данных

Type:

Article

Abstract:

Reaction of 3-(polyfluoroacyl)chromones with hydroxylamine free base proceeds via nucleophilic 1,4-addition followed by opening of the pyrone ring and subsequent cyclization to 4-(polyfluoroalkyl)-4H-chromeno{[}3,4-d]isoxazol-4-ols in good yields. On treatment with trifluoroacetic acid, the isoxazole ring of this annulated heterocyclic system opens to give 3-cyano-2-(polyfluoroalkyl)chromones, which were successfully hydrolyzed with concentrated H(2)SO(4) to afford 3-carbamoyl-2-(polyfluoroalkyl)chromones. On the other hand, oximation of 3-(polyfluoroacyl)chromones with hydroxylamine hydrochloride occurs either at the carbonyl carbon atom connected to the R(F) group or at the C-2 atom to give 3-R(F)C(=NOH)chromones and 5-R(F)-4-salicyloylisoxazole oximes, respectively. The former were easily converted to 3-R(F)-4-salicyloylisoxazoles by simple heating in dimethyl sulfoxide, (C) 2008 Elsevier Ltd. All rights reserved.

Author keywords:

3-(polyfluoroacyl)chromones; hydroxylamine; nucleophilic 1,2-and 1,4-addition; isoxazoles; oximes; 3-cyano- and 3-carbamoyl-2-(polyfluoroalkyl)chromones BENZO-GAMMA-PYRONES; FLUORINATED HETEROCYCLIC-COMPOUNDS; ACTIVE METHYLENE-COMPOUNDS; 1,3-BIS-SILYL ENOL ETHERS; ANTIANAPHYLACTIC AGENTS; CONVENIENT SYNTHESIS; CONJUGATE ADDITION; VERSATILE SYNTHON; 3-FORMYLCHROMONE; 3-ACYLCHROMONES

DOI:

10.1016/j.tet.2008.06.041

Web of Science ID:

ISI:000258271300003

Соавторы в МНС:

Другие поля

Поле	Значение
Month	AUG 18
Publisher	PERGAMON-ELSEVIER SCIENCE LTD
Address	THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
Language	English
Keywords-Plus	BENZO-GAMMA-PYRONES; FLUORINATED HETEROCYCLIC-COMPOUNDS; ACTIVE METHYLENE-COMPOUNDS; 1,3-BIS-SILYL ENOL ETHERS; ANTIANAPHYLACTIC AGENTS; CONVENIENT SYNTHESIS; CONJUGATE ADDITION; VERSATILE SYNTHON; 3-FORMYLCHROMONE; 3-ACYLCHROMONES
Research-Areas	Chemistry
Web-of-Science-Categories	Chemistry, Organic
Author-Email	svy@etel.ru
ResearcherID-Numbers	Moshkin, Vladimir/E-6623-2017
Number-of-Cited-References	86
Usage-Count-Since-2013	7
Journal-ISO	Tetrahedron
Doc-Delivery-Number	335DP