Stereoselective Synthesis of Quaternary Center Bearing Azetines and Their β-Amino Acid Derivatives
作者:Christopher J. MacNevin、Rhonda L. Moore、Dennis C. Liotta
DOI:10.1021/jo7018202
日期:2008.2.1
We describe here the use of a stable, four-membered azetine heterocycle for the preparation of highly substituted β-amino acid derivatives. Imidazolidinone chiral auxiliaries were found to eliminate a competitive reaction pathway that had been present under previously reported conditions for azetine synthesis. The ephedrine derived imidazolidin-2-one 21 was allowed to react as its chlorotitanium enolate
The reaction of α,β-unsaturated nitro compounds with aldehydes or electron deficient olefins, in the presence of a base provides a simple method for the preparation of α-substituted allylic nitro compounds. The initially formed allylic carbanion reacts regioselectively at the position α to the nitro group. The products formed, γ,δ-unsaturated β-nitro alcohols 2 and δ,ε-unsaturated γ-nitro ketones, esters, nitriles, and sulfones 3, can serve as useful synthetic intermediates.
Lucet, Denis; Sabelle, Stephane; Kostelitz, Olivier, European Journal of Organic Chemistry, 1999, # 10, p. 2583 - 2591
作者:Lucet, Denis、Sabelle, Stephane、Kostelitz, Olivier、Le Gall, Thierry、Mioskowski, Charles
DOI:——
日期:——
Solid-Phase Combinatorial Synthesis of Polyisoxazolines: A Two-Reaction Iterative Protocol
作者:Mark J. Kurth、Lisa A. Ahlberg Randall、Kazuya Takenouchi
DOI:10.1021/jo961730l
日期:1996.1.1
Starting from a polymer-bound olefin, iterative application of nitrile oxide 1,3-dipolar cycloaddition and selenide oxidation/elimination steps were employed to deliver a polymer-bound triisoxazoline that can be liberated from the resin by transesterification. When four nitroseleno ethers (2-5) and four capping nitroalkanes (6-9) were employed, a triisoxazoline library (V) of 64 positional isomers