A Novel Catalytic and Highly Enantioselective Approach for the Synthesis of Optically Active Carbohydrate Derivatives
作者:Hélène Audrain、Jacob Thorhauge、Rita G. Hazell、Karl Anker Jørgensen
DOI:10.1021/jo9918596
日期:2000.7.1
yield, high diastereoselectivity, and excellent enantioselectivity. The potential of the reaction is demonstrated by the synthesis of optically active carbohydrates such as spiro-carbohydrates, an ethyl beta-D-mannoside tetraacetate, and acetal-protected C-2-branched carbohydrates. On the basis of X-ray crystallographic data and the absolute configuration of the products, it is proposed that the alkene
Efficient Homologation of Aldehydes to 2,4,6-Alkatrienals by means of an α-(1,3-Dioxenylallyl)boronate
作者:Reinhard W. Hoffmann、Frank Schäfer、Eckart Haeberlin、Thorsten Rohde、Karsten Körber
DOI:10.1055/s-2000-8720
日期:——
The α-dioxenyl-allylboronate 4 allows the direct conversion of aldehydes into the 7-hydroxy-2,4-dienals (6). The latter compounds can be dehydrated to 2,4,6-alkatrienals 7 by means of the Burgess reagent or methanesulfonyl anhydride/Hünig Base.
Regioselective Synthesis of Substituted <i>o</i>-Alkoxyphenol Derivatives through Thermal Benzannulation of Fischer (Alkenylcyclobutenyl)carbene Complexes
A convenient, regioselective, and general synthetic method for producing highly substituted o-phenol-containing polycycles from Fischer (alkenylcyclobutenyl)carbene complexes has been described. The starting complexes have been synthesized by means of the [2 + 2] cycloaddition reaction of (alkenylethynyl)carbene complexes and a range of enol ethers, and in most cases, they have proven to be stable
Largazole and Analogues with Modified Metal-Binding Motifs Targeting Histone Deacetylases: Synthesis and Biological Evaluation
作者:Pravin Bhansali、Christin L. Hanigan、Robert A. Casero、L. M. Viranga Tillekeratne
DOI:10.1021/jm200432a
日期:2011.11.10
The histone deacetylase inhibitor largazole 1 was synthesized by a convergent approach that involved several efficient and high yielding single pot multistep protocols. Initial attempts using tert-butyl as thiol protecting group proved problematic, and synthesis was accomplished by switching to the trityl protecting group. This synthetic protocol provides a convenient approach to many new largazole analogues. Three side chain analogues with multiple heteroatoms for chelation with Zn2+ were synthesized, and their biological activities were evaluated. They were less potent than largazole 1 in growth inhibition of HCT116 colon carcinoma cell line and in inducing increases in global H3 acetylation. Largazole 1 and the three side chain analogues had no effect on HDAC6, as indicated by the lack of increased acetylation of alpha-tubulin.