Pseudoephedrine as a Chiral Auxiliary for Asymmetric Michael Reactions: Synthesis of 3-Aryl-δ-lactones
作者:Jacqueline H. Smitrovich、Geneviève N. Boice、Chuanxing Qu、Lisa DiMichele、Todd D. Nelson、Mark A. Huffman、Jerry Murry、James McNamara、Paul J. Reider
DOI:10.1021/ol0259847
日期:2002.5.1
[reaction: see text] The asymmetric Michael reaction of pseudoephedrine amides is reported. The 1,5-dicarbonyl products are converted to 3-aryl-delta-lactones in a two-step reduction/lactonization sequence. This method provides access to enantiomerically enriched trans-3,4-disubstituted delta-lactones.
Cu(I) Tol-BINAP-Catalyzed Enantioselective Michael Reactions of Grignard Reagents and Unsaturated Esters
作者:Shun-Yi Wang、Shun-Jun Ji、Teck-Peng Loh
DOI:10.1021/ja0666046
日期:2007.1.1
A highly efficient regio- and enantioselective catalytic asymmetric addition of Grignard regeants to α,β-unsaturated esters promoted by the CuI-Tol-BINAP system is described.
The enantioselective construction of a fully functionalized core structure of (-)-CP-263,114 (1), containing most of the required functionality for total synthesis, was conducted through sequential radical fragmentation-reductive olefination.
Syntheses of α,β-Unsaturated Carbonyl Compounds from the Reactions of Monosubstituted Ozonides with Stable Phosphonium Ylides
作者:Yung-Son Hon、Ling Lu、Rong-Chi Chang、Sheng-Wun Lin、Pei-Pei Sun、Chia-Fu Lee
DOI:10.1016/s0040-4020(00)00903-0
日期:2000.11
Ozonides derived from terminal alkenes reacted with 1.3 mol equiv. of stable phosphonium ylides to give (E)-α,β-unsaturated carbonyl compounds in good to excellent yields. No reducing agent is needed in the reaction. However, alkoxyalkyl-substituted ozonides afforded a mixture of (Z)- and (E)-α,β-unsaturated carbonyl compounds under similar condition. The E/Z isomeric ratio is affected by the position
Influence of substitution pattern on intramolecular alkylidene carbene insertion reactions
作者:Ahmed Bourghida、Vincent Wiatz、Martin Wills
DOI:10.1016/s0040-4039(01)01853-6
日期:2001.12
A series of intramolecular alkylidene insertionreactions have been investigated. The nature of the substituents is demonstrated to have a dramatic effect on the outcome. In one example a novel rearrangement is observed.