Access to Wieland-Miescher Diketone-Derived Building Blocks by Stereoselective Construction of the C-9 Quaternary Carbon Center Using the Mukaiyama Aldol Reaction
The Mukaiyama aldol reaction has been used to efficiently install a lateral chain at the C-9 position of the Wieland-Miescher ketone derivative 3 within two steps, representing a shortcut compared to that of the classical sequences. The treatment of the silylated enol ether 8 with a wide range of acetals in the presence of tin tetrachloride led to a the diastereoselective construction of the C-9 quaternary center of 33 new building blocks derived from the Wieland-Miescher ketone derivative 3.
Synthesis of unnatural α-amino esters using ethyl nitroacetate and condensation or cycloaddition reactions
We report here on the use of ethyl nitroacetate as a glycine template to produce α-amino esters. This started with a study of its condensation with various arylacetals to give ethyl 3-aryl-2-nitroacrylates followed by a reduction (NaBH4 and then zinc/HCl) into α-amino esters. The scope of this method was explored as well as an alternative with arylacylals instead. We also focused on various [2 + 3] cycloadditions, one leading to a spiroacetal, which led to the undesired ethyl 5-(benzamidomethyl)isoxazole-3-carboxylate. The addition of ethyl nitroacetate on a 5-methylene-4,5-dihydrooxazole using cerium(IV) ammonium nitrate was also explored and the synthesis of other oxazole-bearing α-amino esters was achieved using gold(I) chemistry.
Gagnot, Glwadys,Hervin, Vincent,Coutant, Eloi P.,Desmons, Sarah,Baatallah, Racha,Monnot, Victor,Janin, Yves L.
supporting information
p. 2846 - 2852
(2018/11/27)
Synthesis and biological activity of n-butylphthalide derivatives
A series of n-butylphthalide derivatives were designed and synthesized. The in vitro activities of these compounds were evaluated by a resting tension of isolated rat thoracic aorta ring assay. Compounds 4g and 4i were found to be more active than n-butylphthalide.
There is provided compounds of formula I, wherein R1 to R7 have meanings given in the description, which are useful in the prophylaxis and in the treatment of arrhythmias, in particular atrial and ventricular arrhythmias.
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Page/Page column 37
(2008/06/13)
Synthesis of Functionalized Hydroxyphthalides and Their Conversion to 3-Cyano-1(3H)-isobenzofuranones. The Diels-Alder Reaction of Methyl 4,4-Diethoxybutynoate and Cyclohexadienes
Several methods have been used in the preparation of functionalized hydroxyphthalides.Metalation of N,N-diethyl-3-methoxybenzamide, followed by reaction with dimethylformamide and hydrolysis, furnished 3-hydroxy-4-methoxy-1(3H)-isobenzofuranone in 52perce
Freskos, John N.,Morrow, Gary W.,Swenton, John S.
p. 805 - 810
(2007/10/02)
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