Enantioselective rearrangements of bicyclo[2.2.1]- and bicyclo[2.2.2]alkene-derived achiral epoxides to ketones

Expanding the Utility of Lithiated Epoxides and Aziridines in Synthesis

“…Unfortunately, attempts to perform these transformations in an enantioselective manner met with only limited success. 22 At this time, an intriguing rearrangement was found to occur with exo,exo-norbornadiene dioxide (Scheme 11). Presumably, the intermediate epoxide, which was a direct result of transannular insertion, was highly strained and so was reduced by the excess of LDA present, to give a meso-diol.…”

Recent Developments in the Chemistry of Lithiated Epoxides

“…Finally in this section, both the rearrangements and 1,2shifts of hydrogens on bicyclic systems shown in Scheme 17 and Scheme 20 have also been carried out enantioselectively. 22,42 However, using either lithium (S,S)-bis(1-phenyl)ethylamide (16, Figure 4) and/or the chiral, non-racemic bislithium bisamide 61 (…”