Treatment of a precooled mixture (-98 °C) of (1S,2S)-
(-)-1-phenylpropylene oxide 1a (ee 99%) and TMEDA (3
equiv) in THF with s-BuLi (3 equiv) (n-BuLi and LDA
were ineffective) gave a cherry-red solution likely to be
ascribed to the lithiooxirane 2a, which proved to be
chemically stable at low temperature (-98 °C) for at least
2 h.