Tandem: Allylic alcohols react with N‐chlorosuccinimide (NCS) in a tandem 1,3‐H shift/CCl bond formation leading to α‐chloroketones and α‐chloroaldehydes. The reactions proceed with complete selectivity to give single constitutional isomers of monochlorinated carbonyl compounds. The utility of the transformation is illustrated by the straightforward synthesis of 4,5‐disubstituted 2‐aminothiazoles