A Facile and Efficient Conversion of Aldehydes into 1,1-Diacetates (Acylals) using Iron(III) Fluoride as a Novel Catalyst
作者:V. T. Kamble、R. A. Tayade、B. S. Davane、K. R. Kadam
DOI:10.1071/ch06166
日期:——
Aldehydes are smoothly converted into the corresponding 1,1-diacetates (acylals) in high yields in the presence of a catalytic amount (0.1 mol-%) of iron(III) fluoride at room temperature. The noteworthy features of the present system are shorter reaction times, chemoselective protection of aldehydes, and solvent-free conditions. The procedure is especially useful for large-scale syntheses as the catalyst
HBF 4 -SiO 2 has been found to be an outstanding catalyst for the protection of carbonyl compounds as acylals under entirely solvent-free conditions. Some of the major advantages of this procedure are high yields, ease of operation, high chemoselectivity, high atom efficiency, and compatibility with other protecting groups.
Conversion of Aldehydes into Geminal Dicarboxylates (Acylals) Catalyzed by Lithium Tetrafluoroborate
作者:Norihiko Sumida、Kuniaki Nishioka、Tsuneo Sato
DOI:10.1055/s-2001-18774
日期:——
A variety of aldehydes react with acid anhydrides in the presence of a catalytic amount of lithium tetrafluoroborate to afford the corresponding geminal dicarboxylates (acylals) in good to excellent yields.
The invention relates to a method and compounds for the preparation of clevidipine butyrate, a very short acting hypertensive calcium antagonist, as well as the synthesis of these compounds useful for the preparation of clevidipine (also known as clevidipine butyrate). Moreover the invention also discloses polymorphic forms of clevidipine butyrate, useful for the preparation of pharmaceutical compositions, and processes to prepare them.
The present invention relates to depot preparations for the targeted release of an aldehyde together with two carboxylic acids, where the released aldehydes are organoleptic substances, specifically fragrances or flavorings, and these depot preparations are prepared by reacting aldehydes with carboxylic anhydrides.