Synthesis of Tubuphenylalanines via Ireland–Claisen Rearrangement

Abstract

The Ireland-Claisen rearrangement is the central step in the synthesis of tubuphenylalanine, a key building block of the highly antitumor-active tubulysins. The rearrangement of substituted β-amino acid allyl esters, in combination with subsequent decarboxylation and oxidative cleavage of the double bond, allows the highly stereoselective introduction of substituents into the α-position of the resulting γ-amino acids.