The Azinothricin family of cyclodepsipeptides are a class of antitumour antibiotics whose antitumour properties are attributed to their ability to selectively repress the expression of genes essential for the progression of the cell cycle from G1 to S phase. They have been shown to inhibit E2F transcription factors, which are critical regulators of mammalian cellular proliferation. This biological observation has made them a potentially important new therapeutic target for the control of proliferative diseases, such as cancer. An asymmetric total synthesis of an A83586C-citropeptin hybrid is presented in this thesis, along with a synthetic route to the azinothricin cyclodepsipeptide. The A83586C- citropeptin hybrid will serve as a useful intracellular probe that will provide valuable insights into the mechanism of the antitumour action of this class, which may contribute to a greater understanding of cancer biology. The cyclodepsipeptide components of these molecules have been assembled via a 2+2+2 -fragment condensation strategy and a HATU-mediated macrolactamisation. In the case of the A83586C-citropeptin hybrid, a chemoselective coupling was performed between the fully elaborated N-hydroxybenzotriazole activated ester and the citropeptin cyclodepsipeptide.