Synthetic studies towards (±)-phthalascidin 650: synthesis of a fully functionalized N-protected-α-amino-aldehyde
作者:Sylvain Aubry、Christian R. Razafindrabe、Benjamin Bourdon、Stéphane Pellet-Rostaing、Marc Lemaire
DOI:10.1016/j.tetlet.2007.10.111
日期:2007.12
An efficient synthesis of fully functionalized N-protected alpha-amino-aldehyde (+/-)-13 as synthetic precursor of the tetra-hydroisoquinoline alkaloid phthalascidin 650 is reported. Starting from sesamol 6, 11 steps are required to give rise to the desired N-protected alpha-amino-aldehyde (+/-)-13 in 25% overall yield. This synthetic strategy involves the elaboration of fully functionalized aromatic aldehyde 7 and its transformation into an alpha-amino-alcohol through a Knoevenagel condensation. The phthalimidomethyl derivative (+/-)-11 was then synthesised from 8 by a Bischler-Napieralski reaction, a diastereoselective hydrogenation of the resultant dihydroisoquinoline and transformed into the corresponding N-protected alpha-amino-aldehyde (+/-)-13. (C) 2007 Elsevier Ltd. All rights reserved.