The preparation of collections of structurally diverse small molecules is a useful tool for studying biology and medicine with chemistry. Herein, we demonstrate the versatility of the pure enantiomers of 2-(2-oxo-ethyl)-piperidine-1-carboxylic acid tertbutyl ester to prepare the biological active alkaloids sedridine, allosedridine, methylsedridine, methylallosedridine, ethylnorlobelol, and coniine in two steps and in a stereoselective way via a reagent-based differentiation. The described syntheses are a demonstration of the versatility of 2-(2-oxo-ethyl)-piperidine-1-carboxylic acid tert-butyl esters as chiral building blocks. (c) 2005 Elsevier Ltd. All rights reserved.
Asymmetric synthesis of Sedum alkaloids via lithium amide conjugate addition
作者:Stephen G. Davies、Ai M. Fletcher、Paul M. Roberts、Andrew D. Smith
DOI:10.1016/j.tet.2009.09.104
日期:2009.12
Conjugateaddition of lithium (R)-N-allyl-N-(α-methylbenzyl)amide or lithium (R)-N-but-3-enyl-N-(α-methylbenzyl)amide to an alkyl hexa-2,4-dienoate or alkyl hepta-2,6-dienoate, followed by ring-closing metathesis of the olefin functionalities within the resultant β-amino ester, generates a range of diastereoisomerically pure azacycles in good yield. These homochiral templates are readily transformed