Design and Synthesis of C6-C8 Bridged Epothilone A

A conformationally restrained epothilone A analogue (3) with a short bridge between methyl groups at C6 and C8 was designed and synthesized. Preliminary biological evaluation indicates 3 to be only weakly active (IC50 = 8.5 µM) against the A2780 human ovarian cancer cell line.