Synthesis And Resolution Of NMR Chiral Auxiliary Reagents

Absolute configurations of chiral compounds have been one of the most important contents in stereochemistry. It is very significant to determine and illustrate spatial configurations of chiral compounds. Since 1970s, some foreign scientists have begun to study this problem and reported a great deal of progress in this field. Now there are some classic methods such as X-ray crystallography analysis, Chiroptical method and NMR method. However, all of these methods have their own limitations, respectively. One of the most important methods is to use 9AMAA and 9AHA as novel chiral auxiliary reagents, with NMR to elucidate absolute configurations. This innovation acts remarkably. However, most of Chinese scientists paid little attention to this field. We have been studying this problem for several years. And some research has been done in the field of synthesis and resolution of these novel chiral auxiliary reagents. Our researches and results are reported in the paper.1 .This paper reviews the NMR methods to determine the absolute stereochemistry of chiral compounds. Especially, it is addressed to recognize absolute configurations of chiral compounds by applying 9AMAA and 9AHA which are modified Mosher's reagents. With the appearance of new chiral auxiliary reagents and development of upfield NMR technique, NMR method can be taken more advantages of. There are many advantages, which can make NMR method more useful. Finally 9AMAA and 9AHA were found to be novel in NMR method. Racemic resolution is the main route for preparation of optical pure chiral compounds. This article also reviews resolution methods of enantiomers. The application and development in the field of chiral separation by CE are reviewed particularly.2.In this chapter, the syntheses of 9AMAA and 9AHA were discussed in detail. Based on Riguera's idea, we also chose anthrance as a reactant. (±)-9AHA could be obtained from anthrance by Friedel-Crafts acylation, reduction, hydrolysis, and (R)- and (S)-9AMAA could be obtained from 9AHA by methylation, hydrolysis, resolution. As a result, some important intermediates and racemes of 9AMAA and 9AHA were obtained in our experiments. Various reaction conditions were investigated and the optimum...