US EPA

7417583 

Journal Article 

Reactions of cyclopropanone acetals with alkyl azides: carbonyl addition versus ring-opening pathways 

Grecian, S; Desai, P; Mossman, C; Poutsma, JL; Aubé, J; , 

2007 

Yes 

Journal of Organic Chemistry
ISSN: 0022-3263
EISSN: 1520-6904 

AMER CHEMICAL SOC 

WASHINGTON 

72 

25 

9439-9447 

English 

17985920 

10.1021/jo0711034 

WOS:000251313600004 

https://pubs.acs.org/doi/10.1021/jo0711034
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The Lewis acid-mediated reactions of substituted cyclopropanone acetals with alkyl azides were found to strongly depend on the structure of the ketone component. When cyclopropanone acetal was treated with alkyl azides, N-substituted 2-azetidinones and ethyl carbamate products were obtained, arising from azide addition to the carbonyl, followed by ring expansion or rearrangement, respectively. When 2,2-dimethylcyclopropanone acetals were reacted with azides in the presence of BF3.OEt2, the products obtained were alpha-amino-alpha'-diazomethyl ketones, which arose from C2-C3 bond cleavage of the corresponding cyclopropanone, giving oxyallyl cations that were captured by azides. Aryl-substituted cyclopropanone acetals, when subjected to these conditions, afforded [1,2,3]oxaborazoles exclusively, which were also the result of C2-C3 bond rupture, azide capture, and then loss of nitrogen. In the reactions of n-hexyl-substituted cyclopropanone acetals with alkyl azides, a mixture of 2-azetidinones and regioisomeric [1,2,3]oxaborazoles was obtained. The reasons for the different behavior of the various systems are discussed. 

Addition reactions; Chemical bonds; Ketones; Molecular structure; Positive ions; Alkyl azides; Cyclopropanone acetals; Lewis acids; Nitrogen compounds; acetal derivative; azetidinone derivative; azide; carbonyl derivative; cation; cyclopropane derivative; ketone; ketone derivative; Lewis acid; nitrogen; pyrrole derivative; urethan; article; chemical bond; chemical reaction; chemical structure; reaction analysis; ring opening; Acetals; Azides; Cyclopropanes; Ketones; Models, Chemical; Molecular Structure; Stereoisomerism