Enantioselective synthesis of cis-2-oxazoline-4-carboxylates by Lewis acid catalyzed formal [3+2] cycloadditions of 5-alkoxyoxazoles with aldehydes

Article abstract of DOI:10.1016/S0040-4039(97)10752-3

Formal [3+2] cycloaddition of 2-o-methoxyphenyl-5-methoxyoxazole with benzaldehyde, m- and p-substituted benzaldehydes in the presence of 30 mol% of (R)-methylaluminum β-binaphthoxide, which was prepared from (R)-2,2'-dihydroxy-1,1'-dinaphthyl and 1.1 - 1.05 equiv. of trimethylaluminum, gave cis-2-oxazoline-4-carboxylates in high enantoselectivity.