O-Alkenyl Hydroxylamines: A New Concept for Cyclofunctionalization
摘要:
Treatment of O-homoallylhydroxylamines with palladium(II) and copper(II) in the presence of a base, methanol, and carbon monoxide results in the formation of isooxazolidines. An electron-withdrawing group on the hydroxylamine nitrogen is essential. When carbamate groups are used the products are formed exclusively as their cis isomers.
A total synthesis of (+)-negamycin through isoxazolidine allylation
作者:Roderick W. Bates、Rab'iah Nisha Khanizeman、Hajime Hirao、Yu Shan Tay、Patcharaporn Sae-Lao
DOI:10.1039/c4ob00537f
日期:——
The β-amino acid antibiotic (+)-negamycin has been synthesised in ten steps from epichlorohydrin via Sakurai allylation of an isoxazolidine intermediate. The key allylation reaction proceeded with complete trans-selectivity, which is attributed to electrostatic attraction between the chlorine atom and the iminium ion in the Sakurai intermediate.
<i>O</i>-Alkenyl Hydroxylamines: A New Concept for Cyclofunctionalization
作者:Roderick W. Bates、Kanicha Sa-Ei
DOI:10.1021/ol026701d
日期:2002.11.1
Treatment of O-homoallylhydroxylamines with palladium(II) and copper(II) in the presence of a base, methanol, and carbon monoxide results in the formation of isooxazolidines. An electron-withdrawing group on the hydroxylamine nitrogen is essential. When carbamate groups are used the products are formed exclusively as their cis isomers.