AsymmetricvinylogousMannichreaction (VMR) of 2-(tert-butyldimethylsilyloxy)furan (TBSOF, 1) with (RS)- or (SS)-t-BS-imines (3) furnished 5-aminoalkylbutenolides 7a–k in 75–87% yields with anti/syn ratios ranging from 75:25 to 97:3. Butenolides 7a–f,k were readily converted into substituted lactones 8 and 5 and 6-substituted 5-hydroxypiperidin-2-ones 11a–g, which are, in turn, key intermediates for
Concise asymmetric synthesis of (−)-deoxoprosophylline
作者:Ru-Cheng Liu、Jin-Hu Wei、Bang-Guo Wei、Guo-Qiang Lin
DOI:10.1016/j.tetasy.2008.12.014
日期:2008.12
An efficient asymmetricsynthesis of the 2-hydroxymethyl 3,6-disubstituted piperidine alkaloid, (−)-deoxoprosophylline, is described. The key step of this route is the SmI2-mediated cross-coupling of chiral N-tert-butanesulfinyl imine 9 with aldehyde 11 to construct hydroxymethyl-β-amino alcohol 12b in 83% yield and high diastereoselectivity (>99%, de).
Asymmetric total synthesis of (2S,3S)-3-hydroxypipecolic acid
作者:Subhash P. Chavan、Nilesh B. Dumare、Kishor R. Harale、Uttam R. Kalkote
DOI:10.1016/j.tetlet.2010.11.062
日期:2011.1
A synthetic route to (2S,3S)-3-hydroxypipecolic acid was achieved from readily available nonchiral pool starting material cis-2-butene-1,4-diol and involved Claisen orthoester rearrangement, Sharpless asymmetric dihydroxylation and intramolecular lactamisation of azido lactone as the key steps. (C) 2010 Elsevier Ltd. All rights reserved.