Diastereoselective syntheses of 2-amino propargyl alcohols. Chiral building blocks for enantiopure amino γ-lactones and 5-hydroxy-piperidinone derivatives
摘要:
alpha-Dibenzylamino aldehydes, derived from the corresponding natural alpha-amino acids, react with metal acetylides to yield anti-amino propargyl alcohols in good yield and diastereomeric excess. syn Amino alcohols are prepared from the. anti diastereo-isomers and all of them are elaborated in few steps to enantiopure amino lactones and hydroxy-piperidin-2-ones. (c) 2006 Elsevier Ltd. All rights reserved.
Synthesis and γ-secretase activity of APP substrate-based hydroxyethylene dipeptide isosteres
作者:Alan Nadin、Andrew P. Owens、José L. Castro、Timothy Harrison、Mark S. Shearman
DOI:10.1016/s0960-894x(02)00840-5
日期:2003.1
Two new APP substrate-based hydroxyethylene isosteres (AT and VI) were prepared and their dipeptide conjugates shown not to inhibit the gamma-secretase-mediated formation of either Abeta1-40 or Abeta1-42. The FG isostere and a des-hydroxy hydroxyethylene isostere also gave inactive compounds. Conversely, a number of compounds containing the intact substrate-unrelated Phe-Phe (FF) hydroxyethylene isostere
Aldol reaction of N,N-dibenzyl valinal with propiolic acid ethyl ester derived lithium reagent provides anti-aminoalcohol 8 and syn-aminoalcohol 9, which are converted into the lactone 6 via two different routes. Alkylation of 6 followed by lactone ringopening afford the acid 2a, which is coupled with the amine 3 and 5-methylisoxazole-3-carboxylate acid 1, respectively, to deliver AG7088.