of cis-2b is worth noting as, in contrast to what was found
by our group12a for lithiated cis-disubstituted oxazolinyloxiranes
and by Molander22 for silicon-stabilized cis-tertbutyl-
substituted oxiranyllithiums, the strain created in
forcing the methyl and the phenyl groups both on the
same side of the oxirane ring of 2b did not promote any
interconversion between cis-2b and trans-2a. Moreover,
the observed diastereo- and enantiospecificity was not
time dependent.