Practical Synthesis of Optically Pure Menthylamines Starting from Racemic Neomenthol
作者:Siegfried Waldvogel、Nina Welschoff
DOI:10.1055/s-0030-1258295
日期:2010.11
scalable route to racemic and highly enantiomerically enriched menthylamines exploits the technical product rac-neomenthol as the starting material. The elaborated protocol is based on nucleophilic substitution of the hydroxy moiety by azide. Subsequent reduction and resolution with tartaric acid provides the desired optically enriched menthylamines. amines - azides - chiral resolution - reduction - terpenoids
Dihydroisoquinolinium salts: catalysts for asymmetric epoxidation
作者:Philip C. Bulman Page、Gerasimos A. Rassias、David Barros、Donald Bethell、Mark B. Schilling
DOI:10.1039/b002156n
日期:——
A range of dihydroisoquinolinium salts has been prepared and tested as asymmetric epoxidation catalysts in an investigation of the reaction mechanism and the factors affecting enantioselectivity in this process.
p-Toluenesulfonyl (Tosyl) and nitrobenzenesulfonyl (Nosyl) are two of the most common sulfonyl protectinggroups for amines in contemporary organic synthesis. While p-toluenesulfonamides are known for their high stability and robustness, their use in multistep synthesis is plagued by difficult removal. Nitrobenzenesulfonamides, on the other hand, are easily cleaved but display limited stability to