First Practical Protection of α-Amino Acids as N,N-Benzyloxycarbamoyl Derivatives
摘要:
The consecutive treatment of N-Cbz amino protected compounds with LiHMDS and CbzCl provides a practical method for the preparation of N,N-benzyloxycarbamoyl (NN-di-Cbz) derivatives in good yield. When alpha-amino acids are used the protection occurs without racemization. The method is compatible with a wide range of other functional and protecting groups. The procedure is also valid for the synthesis of mixed N,N-carbamoyl derivatives.
(Aka) to quantify the nucleophilicity of hydroxyl groups in glycosylation influenced by the steric, electronic and structural effects, providing a connection between experiments and computer algorithms. The subtle reactivity differences among the hydroxyl groups on various carbohydrate molecules can be defined by Aka, which is easily accessible by a simple and convenient automation system to assure