Synthesis of 1,2‐Amino Alcohols by Sigmatropic Rearrangements of 3‐(N‐Tosylamino)allylic Alcohol Derivatives

Sigmatropic rearrangements of 3-(N-tosylamino)allylic alcohol derivatives, a particular subclass of functionalized enamides, have been investigated. Whereas the presence of the nitrogen atom alters the stereochemical outcome of Ireland-Claisen rearrangements of glycolates derived from such substrates, [2,3]-Wittig rearrangements of α-allyloxy acetamides or propargylic ethers derivatives provide access to a wide variety of functionalized 1,2-amino alcohols usually with high levels of stereocontrol, as well as to heterocyclic compounds. The stereoselectivity issues of these rearrangements (1,2-diastereoselectivity, auxiliary-induced diastereoselection, chirality transfer, and double stereodifferentiation) were thoroughly investigated.