Asymmetric synthesis with new chiral auxiliaries derived from isosorbide
作者:R. Tamion、F. Marsais、P. Ribereau、G. Queguiner
DOI:10.1016/s0957-4166(00)82213-2
日期:1993.1
Chiral aminoethers derived from carbohydrates have been used for asymmetric alkylation of phenylacetic amides giving diastereoisomeric excess up to 83%.
Bio-Based Amides from Renewable Isosorbide by a Direct and Atom-Economic Boric Acid Amidation Methodology
aromatic carboxylic acids. The extension of the scope of the reaction to eight Boc-protected amino acids is also described, the products being obtained in moderate to good yields. A preliminary screening of these new potential organocatalysts was carried out for the aldolization of isatin.
Synthesis of both monobenzenesulfonates of isosorbide (1,4:3,6-dianhydrosorbitol) was regioselectively achieved in high yields via a three-step sequence. These monoesters were O-alkylated before being reacted with various primary amines to give the corresponding amino ethers. The full control of regioselectivity led either to the exo-exo or endo-endo isomers. In an independent pathway, isosorbide derived