83075-05-2Relevant academic research and scientific papers
Heteropoly acids as heterogeneous catalysts for thioacetalization and transthioacetalization reactions
Firouzabadi,Iranpoor,Amani
, p. 59 - 62 (2007/10/03)
Heteropoly acids are effective solid catalysts for the thioacetalization of carbonyl compounds. Tungstophosphoric acid (H3PW12O40), was found to be an effective and a highly selective catalyst for the thioacetalization of aldehydes, ketones and for the transthioacetalization of acetals, acylals and O,S-acetals which proceeded in excellent yields in the absence of solvent. The catalyst has also been successfully applied to the chemoselective conversion of α- or β-diketones and a β-keto ester into the corresponding dithioacetals. Sterically hindered carbonyl compounds such as camphor and benzophenone were also converted to their corresponding thioacetals in refluxing petroleum ether in 89-94percent yields. Surprisingly, anthrone was reduced to anthracene in 91percent yield.
Enantioselective Synthesis of 2-(2-Methyl-1,3-dithiolan-2-yl)ethanoles. - New Agents for the Preparation of Optically Active β-Hydroxy Ketones
Stahl, Ingfried,Wrabletz, Frank,Gosselck, Juergen
, p. 371 - 376 (2007/10/02)
The 2,2-disubstituted 1,3-dithio acetales 3, available by cyclothioacetalization of the 1,3-diketones 1 with the 1,3-dithioles 2, are reduced in good optical yields with the chiral auxiliary 4 to the 2-(2-methyl-1,3-dithiolan- and -1,3-dithian-2-yl)ethano
FORMATION AND NMR STUDY OF SOME CYCLIC β-KETODITHIOACETALS
Barros, M. T.,Geraldes, C. F. G. C.,Maycock, C. D.,Silva, M. I.
, p. 2283 - 2288 (2007/10/02)
An efficient method has been found for the preparation of cyclic monodithioacetals of 1,3-dicarbonyl compounds using boron trifluoride etherate as the acid catalyst.Asymmetric 1,3-diketones react regioselectively in most of the cases tried.A study of the
Preparative Aspects of 1,3-Dithiolanes Synthesizable from β-Dicarbonyl Compounds
Stahl, Ingfried,Schramm, Berthold,Manske, Rainer,Gosselck, Juergen
, p. 1158 - 1172 (2007/10/02)
The reaction of 1,2-ethanedithiol (1) with the β-dicarbonyl compounds 2 leads to the 1,3-dithiolanes 3 which are accessible to regioselective reactions at the free carbonyl function.Thus the derivatives of the β-keto acid esters can be hydrolyzed to give the corresponding carboxylic acids 4 which make the ester group modified 1,3-dithiolanes 3 accessible in good yields.Addition of trimethyloxonium tetrafluoroborate produces the monodithiolanium salts 6 which on hydrolysis rapidly decompose into 2 and the vinyl thioethers 8.Reaction of 3 with Grignard reagents 10 yields the 2-(2-hydroxyalkyl)-1,3-dithiolanes 11.Dethioacetalization of 11 with HgO/BF3 leads to the β-hydroxy ketones 12.The retro reaction of 3 leads to the basic compounds 2 which, however, are obtained only in moderate yields. - Finally the performance of the sensitive silylenol ether 13 starting from 3g is described.
