Cationic Reduction of Bastadin-4 to Bastadin-5. Preparation of 5-[<sup>2</sup>H]-Bastadin-5 by Site-Specific Isotopic Labeling
作者:Makoto N. Masuno、Tadeusz F. Molinski
DOI:10.1021/np020382h
日期:2003.1.1
A chemoselective conversion of bastadin-4 to the important Ca2+ channel modulator bastadin-5 (1a) has been achieved using cationic hydrogenation (Et3SiH, TFA, 60%). Specifically deuterated bastadin-5 (1b, >95 at. %) was prepared following this method and the simplified H-1 NMR H-5/H-2-6 spin system of 1b exploited to study temperature-dependent macrocyclic ring dynamics.
A General Method for the Synthesis of Bastaranes and Isobastaranes: First Total Synthesis of Bastadins 5, 10, 12, 16, 20, and 21
作者:Elias A. Couladouros、Emmanuel N. Pitsinos、Vassilios I. Moutsos、Georgios Sarakinos
DOI:10.1002/chem.200400904
日期:2005.1
A general strategy for the synthesis of twenty naturally occurring bastadins (all but bastadin 3) is presented. A key retrosynthetic disconnection of the two amide bonds, common in all target molecules, bisects the macrocyclic core into two diaryl ether fragments, an alpha,omega-diamine (western part) and an alpha,omega-dicarboxylic acid (eastern part). Efficient preparation of the synthetically challenging