SYNOPSISThe new chiral monomer 3-oxobornyl methacrylate (OBMA) was synthesized from (+)-camphor. Homopolymerization of OBMA and copolymerization of OBMA with styrene were carried out in benzene in the presence of AIBN. The effect of concentration, solvent, temperature, and reaction time on the copolymerization were investigated. It was found that the absolute value of the specific rotation of poly(0BMA-co-St) increased by increasing the OBMA unit content. A small deviation from linearity was observed, which suggests that asymmetry is not introduced into the copolymer main chain. Temperature and solvent effects on the specific rotation of the chiral polymers were investigated. The results suggest that chiral polymers contain no helix conformation. Inspecting the spectra of optical rotatory dispersion and circular dichroism, we found that the chiral polymers exhibit a strong negative Cotton Effect around 310 nm. 0 1996 John Wiley & Sons, Inc.
I NTRO D U CTlO NOptically active compounds have attracted great attention because living systems are chiral. Proteins and nucleic acids process chiral characteristic structures that are related closely to their functions. Because of chirality, living organisms usually show different biological responses to one or the other of a pair of enantiomers or optical isomers whether they are drugs, pesticides, or wastes.Synthesis of chiral compounds from achiral reagents always yields the racemic modification. This is simply one aspect of the more general rule: Optically inactive reagents yield optically inactive products. Optically inactive racemates, however, can be separated in the chiral environment. A wide variety of polymeric chiral stationary phases (CSP) have been developed for the separation of enantiomers by means of high-performance liquid chromatography (HPLC). '-4 During the course of our investigations on the synthesis of both monomers and polymers containing chiral groups derived from (+)-camphor, it was found that polymers with pendant chiral bornyl groups are effective for asymmetric induction re-* To whom correspondence should be addressed. action^.^-^ In our previous paper, we synthesized chiral polymers poly(CP0-co-TDI) and poly(CP0-co-IPDI) from (+)-camphor and studied their applications on the optical resolution by the HPLC technique? In connection with studies on the catalytic functionality of chiral polymers having bornyl moieties, the synthesis and polymerization of a new chiral monomer 3-oxobornyl methacrylate (OBMA) were studied. This article describes synthesis of the optically active OBMA monomer from (+)-camphor and its polymerization under various conditions. Effects of temperature, concentration, and solvent on the polymerization were investigated. The optical activity and stereo characteristics of the chiral polymers were also investigated.
EXPERIMENTAL
MeasurementInfrared (IR) spectra were recorded on a Jasco VALOR I11 FT-IR spectrophotometer. Nuclear magnetic resonance (NMR) spectra were performed on a Bruker-100, high-resolution NMR spectrometer. ...
