A Diastereoselective Total Synthesis of <i>trans</i>-Trikentrin A: A Ring Contraction Approach
作者:Luiz F. Silva、Marcus V. Craveiro
DOI:10.1021/ol8023105
日期:2008.12.4
obtain the polyalkylated indole (+/-)-trans-trikentrin A was developed. The synthesis of this natural alkaloid features a thallium(III)-mediated ring contraction reaction to obtain the trans-1,3-disubstituted five-membered ring in a diastereoselective manner. Thallium(III) is chemoselective in this rearrangement, reacting with the olefin without oxidation of the indolemoiety. Other key transformations
Two pathways towards the construction of the trikentrin skeleton are presented, one leading to the total synthesis of (+/-)-cis-Trikentrin A (1). The key step is the intramolecular Heck coupling of the triflate 21 to form the five-membered ring of the indenes 22 and 23.