The discovery that post‐translational farnesylation of Ras oncoprotein was an essential step in exercising its biological effect led to the design of farnesyl protein transferase inhibitors (FTIs) in order to control growth of tumors bearing Ras mutations. Pre‐clinical studies on murine models have confirmed their inhibitory effect on tumor growth and enabled clinical development. R115777 (ZARNESTRATM) is currently undergoing clinical evaluation and recent studies have confirmed its antitumor potential and low toxicity. We wish to describe here the chemical synthesis routes that our group have developed to access ZARNESTRATM. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)

This article presents the structure elucidation of four new compounds, formed during the hemisynthetic preparation of trabectedin, an anti-tumor natural product from Ecteinascidia turbinata. We report herein on the use of UV, MS and NMR spectroscopic data along with (1)H and (13)C spectral assignments obtained by means of 1D and 2D homo- and heteronuclear NMR techniques.