entry toward thienamycin and related compounds. The copper(I)-mediated reaction between five-membered cyclic nitrones and terminal acetylenes, leading to the assembly of the basic skeleton of carbapenemantibiotics is described. The diastereoselectivity of this cycloaddition–rearrangement cascade, a process known as the Kinugasa reaction, with respect to the structure and configuration of both substrates
METHOD FOR THE PREPARATION OF CARBAPENAM COMPOUNDS
申请人:Chmielewski Marek
公开号:US20140148595A1
公开(公告)日:2014-05-29
The subject of the present invention is a method of the preparation of compounds containing the core skeleton of carbapenem antibiotics, novel intermediate compounds used in this method, a method of the preparation of the intermediate compounds as well as the use of the intermediate compounds in the production of carbapenem antibiotics.
Diastereoselective synthesis of propargylic N-hydroxylamines via NHC–copper(<scp>i</scp>) halide-catalyzed reaction of terminal alkynes with chiral nitrones on water
作者:Ł. Woźniak、O. Staszewska-Krajewska、M. Michalak
DOI:10.1039/c4cc08742a
日期:——
first NHC-copper(I)-halide catalyzed addition of terminal alkynes to enantiomerically pure nitrones on water is described. This reaction provides a straightforward access to propargylic N-hydroxylamines in excellent yield and with excellent stereoselectivity (up to 97%). The presented methodology was applied as a key step in the formal synthesis of (-)-lentiginosine.
shifts of the H-2 proton and geminal protons of the protected alkoxymethyl group at the C-2 carbon atom. The differences of 1 H NMR chemical shifts of these protons fall in two ranges of about 3.3-3.7 ppm, and 4.0-4.4 ppm. This observation can be attributed to the influence of the anisotropy of the neighboring carbonylgroup and can be easily correlated with configuration at the bridgehead carbon atom
A direct approach to the synthesis of indolizidine and quinolizidine scaffolds of iminosugars is described. The presented strategy is based on a one-pot sugar lactam reduction with Schwartz’s reagent followed by a diastereoselective Mannich/Michael tandem reaction of the resulting sugar imine with Danishefsky’s diene. The stereochemical course of the investigated reaction has been explained in detail