Beta-amino alcohol chiral auxiliaries have been used in organometallic chemistry in recent years as a valuable aid for promoting catalytic stereoselective synthesis. Several excellent beta-amino alcohol chiral auxiliaries have been developed aver this period, but the preparation of many of these auxiliaries involves lengthy synthetic schemes or separation procedures that are impractical in commercial applications.
Researchers at the University of California have developed the first convenient and inexpensive synthesis of enantiomerically-pure terpene-based beta-amino alcohol chiral auxiliaries for use in stereoselective organometallic chemistry. The UC synthesis is based upon epoxidation of terpenes. Other groups that have tried epoxidation have not been able to avoid generation of diastereomeric epoxide mixtures, which are difficult and expensive to separate and purify using existing techniques. The UC researchers, however, achieved a breakthrough in processing such mixtures to kinetically resolve them to yield an enantiomerically-pure form.
The conformation of the resulting terpene-based beta-amino alcohol chiral auxiliary is such that both the amino and hydroxyl moieties are in an equatorial position, an orientation that has proven to be highly effective in catalytic enantioselective alkylation of carbonyl compounds. Thus, the stereoselective synthesis of these and other organic compounds can be economically done in batch-sized lots using this invention.