The hazards associated with this alkyl isocyanide can be largely avoided by employing tosylmethyl isocyanide (TosMIC). The reaction of TosMIC with aldehydes under basic conditions affords 5-substituted oxazoles directly, as described by van Leusen et al., 8 although this method is limited by the availability and/or stability of the requisite aldehyde. The reaction of the TosMIC anion with carboxylic acid chlorides 8 , anhydrides 8 and esters 9 has also been carried out by ...