Synthesis of Optically Active β- or γ-Alkyl-Substituted Alcohols through Copper-Catalyzed Asymmetric Allylic Alkylation with Organolithium Reagents
作者:Sureshbabu Guduguntla、Martín Fañanás-Mastral、Ben L. Feringa
DOI:10.1021/jo401536u
日期:2013.9.6
An efficient one-pot synthesis of optically active β-alkyl-substituted alcohols through a tandem copper-catalyzedasymmetricallylicalkylation (AAA) with organolithium reagents and reductive ozonolysis is presented. Furthermore, hydroboration–oxidation following the Cu-catalyzed AAA leads to the corresponding homochiral γ-alkyl-substituted alcohols.
herein is the first synthesis of the monobenzannulated 5,5-spiroketals danshenspiroketallactone and epi-danshenspiroketallactone, two components of the traditional Chinese medicine Danshen. Key features of the synthesis include a directed metallation-lactonisation sequence to install the isobenzofuranone moiety and an oxidative radical cyclisation to afford the monobenzannulated 5,5-spiroketal. Danshen
Synthesis of All Four Stereoisomers of (E)-Vitamin KT (Phylloquinone), Analysis of Their Diastereoisomeric and Enantiomeric Purities and Determination of Their Biopotencies
procedure. A HPLC method was developed which separates with remarkable efficiency all four stereoisomers of (E)- as well as three out of the four stereoisomers of (Z)-vitamin K1 on opticallyactive poly(trityl methacrylate) as the chiral stationary phase supported on Nucleosil. By this method, the stereoisomeric content of the stereoisomers 1b-d synthesized was shown to be in the range of 96-98 %,
Efficient stereoselective synthesis of natural α-tocopherol (vitamin E)
作者:Claudio Fuganti、Piero Grasselli
DOI:10.1039/c39790000995
日期:——
containing ca. 87% of the (2S)-isomer (3), which is converted into (3R,7R)-3,7,11-trimethyldodecan-1-ol (8), a key intermediate in the synthesis of naturalα-tocopherol (19); the same alcohol (8) and its lower homologue (16), which is also an intermediate in the same synthesis, are both obtained in optically pure form from the acid (9).