In this report, we present a highly efficient approach for the synthesis of β,γ-disubstituted γ-butyrolactone motifs. This newly developed strategy is based on the combination of a diastereoselective aldol and a nickel carbene-mediated γ-butyrolactonization and uses an effective intramolecular ring closure to rapidly access a range of functionalized chiral γ-butyrolactones. This single-step approach
Isolation and total syntheses of two new alkaloids, dubiusamines-A, and -B, from Pandanus dubius
作者:Mario A. Tan、Mariko Kitajima、Noriyuki Kogure、Maribel G. Nonato、Hiromitsu Takayama
DOI:10.1016/j.tet.2010.02.073
日期:2010.5
Chemical investigation of the crude base of Pandanus dubius led to the isolation of two new alkaloids, dubiusamine-A (1) and dubiusamine-B (2). The structures of the two alkaloids including their absolute configuration were unambiguously confirmed by 1D and 2D NMR analysis and asymmetric total synthesis. (C) 2010 Elsevier Ltd. All rights reserved.