NEW PERMETHYL-SUBSTITUTED BETA-CYCLODEXTRIN POLYSILOXANES FOR USE AS CHIRAL STATIONARY PHASES IN OPEN-TUBULAR COLUMN CHROMATOGRAPHY

Heptakis(2,3-di-O-methyl)-6-O-tosyl-beta-cyclodextrin (2) was prepared from heptakis(2,3-di-O-methyl)-beta-cyclodextrin (1) in a 31 % yield. The tosyl group of 2 was substituted by p-(allyloxy)phenyl in a yield of 74 % to produce 6-O-(p-(allyloxy)phenyl)heptakis(2,3-di-O-methyl)-beta-cyclodextrin (3). This material was derivatized at the other 6-positions to produce persubstituted 6A-O-(p-(allyloxy)phenyl)-beta-cyclodextrins 4, 5, and 8. Permethylated 6-O-tosyl-beta-cyclodextrin 9, which was used for the preparation of 10-12, was obtained from 2 almost quantitatively. 6-O-(tert-Butyldimethylsilyl)-(heptakis(2,3-di-O-methyl)-beta-cyclodextrin (13) was also obtained from 1 in a 33% yield. Permethylated 6A-deoxy-6A-methylene-beta-cyclodextrin (17) was prepared from 13 by a 4-step process. Seven new permethyl-substituted beta-cyclodextrins bound to polymethylsiloxane were prepared by a hydrosilylation reaction of the permethyl-substituted monoalkenyl-beta-cyclodextrins with polyhydromethylsiloxane. The polymeric phases provide excellent enantiomeric separation of a variety of chiral solutes in open tubular column supercritical fluid chromatography (SFC) and gas chromatography (GC).