ISSN:
0075-4617
Keywords:
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Description / Table of Contents:
Seven-Membered Rings by 1,5-Cycloadditions, II1). - Octahydrofurano[3,2-f]-1,4-oxazepines and Octahydro-6H-pyrano[3,2f]-1,4-oxazepines5-Methyl-2,3-dihydrofuran reacts with 1,3-oxazolidines 2 a and 2e in dimethyl sulfoxide in the presence of Lewis acids to give 8a-methyloctahydrofurano[3,2-f]-l,4-oxazepines 3a and 3b by means of a ring-opening 1,5-cycloaddition. Analogously, 3,4-dihydro-2H-pyran reacts with 1,3-oxazolidines 2a- e to give octahydro-6H-pyrano[3,2-f]-1,4-oxazepines 3c- g. Hydrogenolytic removal of the N-benzyl groups from 3b and 3g affords 3h and 3i, which react with isocyanates and isothiocyanates to give the N-carbamoyl arid N-thiocarbamoyl derivatives 3k- p. Compound 3c is transformed into N-methyl-N-(3,4-tetrahydro-2H-pyran-3-ylmethyl)-2-aminoethanol (4) by reaction with lithium aluminium hydride/aluminium chloride.
Notes:
5-Methyl-2,3-dihydrofuran gibt mit den 1,3-Oxazolidinen 2 a und 2e in Dimethylsulfoxid bei Gegenwart von Lewis-Säuren in einer ringöffnenden 1,5-Cycloaddition die 8a-Methyl-octahydrofurano[3,2f]-1,4-oxazepine 3a und 3 b. In gleicher Weise führt 3,4-Dihydro-2H-pyran mit den 1,3-Oxazolidinen 2a- e zu den Octahydro-6H-pyrano[3,2-f]-1,4-oxazepinen 3c- g. Hydrogenolytische Abspaltung der N-Benzylgruppen von 3b und 3g gibt 3h bzw. 3i, welche mit Isocyanaten und Isothiocyanaten zu den entsprechenden N-Carbamoyl- und N-Thiocarbamoylderivaten 3k- p reagieren. Umsetzung mit Lithiumaluminiumhydrid/Aluminiumchlorid überfuhrt 3c in N-Methyl-N-(3,4-tetrahydro-2H-pyran-3-ylmethyl)-2-aminoäthanol (4).
Additional Material:
1 Tab.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jlac.197619761009
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