Oxazolidine-2-thiones have been used as chiral auxiliaries for a wide variety of synthetic transformations. 1 These five-membered heterocycles are commonly prepared by the condensation of carbon disulphide with β-amino alcohols. 2-4 Oxazolidine-2-thiones are used in the synthesis of (3S,4S)-[(R)-1'-((tert-butyldimethylsilyl)oxy)ethyl]-2-azetidinone (2), a key carbapenem intermediate. 5-7 In the course of our ongoing project for the synthesis of 2, a method for ...