118987-64-7Relevant academic research and scientific papers
ALKYATION STUDIES OF 5-EXO-METHYLENE SUBSTITUTED ISOXAZOLIDINES
Padwa, Albert,Carter, Stephen P.,Chiacchio, Ugo,Kline, Donald N.,Perumattam, John
, p. 2639 - 2646 (2007/10/02)
1,3-Dipolar cycloaddition of nitrones to phenylsulphonylallene gives in high yield and with complete regiospecificity 5-methyleneisoxazolidines.These on treatment with base and subsequent reaction with electrophiles afford both α- and γ-substituted products.With methyl iodide as the electrophile, only the α-methylated product was isolated.In contrast, reaction of the 5-exo-methylene-4-phenylsulphonylisoxazolidine with allyl bromide afforded the γ-allyated product.Formation of this was shown to be via direct γ-attack, rather than by α-attack, followed by a 3,3-sigmatropic rearrangement.Further studies show that the product ratio is controlled by a sensitive interplay between thermodynamic and steric factors and is very dependent on the nature of the electrophile used.
