Homochiral beta-sulfinyl nitrones can be prepared from secondary amines in three steps. Enantioselective synthesis of defensive alkaloid (+)-euphococcinine (9) has been accomplished by means of diastereoselective allylation of homochiral beta-sulfinyl nitrone (13) followed by intramolecular 1,3-dipolar cycloaddition reaction.
The reaction of nitrones with (R)-(+)-methyl p-tolyl sulfoxide anion; asymmetric synthesis of optically active secondary amines
作者:Shun-Ichi Murahashi、Jun Sun、Tomoyasu Tsuda
DOI:10.1016/s0040-4039(00)77646-5
日期:1993.4
α-substituted N-hydroxylamines have been prepared by the addition of (R)-(+)-and (S)-(−)-methyl p-tolyl sulfoxide anions to nitrones highly efficiently. This method is applicable to the synthesis of optically active N-hydroxy tetrahydroisoquinoline derivatives 6a–6e, which are important precursors of various isoquinolinealkaloids such as (R)-(+)-salsolidine. (8). Furthermore, the reaction of nitrones bearing