Synthesis, structure and reactivity of an evans-type bis(imide) derived from a C-2-symmetric bis(oxazolidinone). A reluctant chiral auxiliary

This paper describes the enantiospecific synthesis of the C-2-symmetric bis (oxazolidinone) 9 from (-)-1,4-di-O-benzyl-L-threitol (3). Compound 9 was i ntended for use as a bifunctional chiral auxiliary in asymmetric alkylation and aldol reactions. However, in the presence of strong non-nucleophilic b ases the bis(imide) derivative 10 (the structure of which has been studied in detail by means of NMR spectroscopy, X-ray crystallography and computati onal methods) did not react with external electrophiles. This lack of react ivity has been interpreted on the basis of a conformational analysis of 10.