Asymmetric Synthesis of Axially Chiral Spiro Aziridines and Spiro Thiazolidinethiones from Sulfonyl Bicyclobutanes.

The synthesis of chiral 1-aza-spiro[2,3]hexanes and spiro thiazolidinethiones possessing axial as well as point chirality was accomplished. The process involved Cs2CO3-mediated ring opening of bicyclobutane derivatives containing chiral sulfinamides. The procedure is operationally simple and does not involve either expensive multimetal catalysis or arduous experimental procedures and/or transformations.