LookChem

https://www.lookchem.com/CASDataBase_732-26-3.htm Flash vacuum pyrolysis (FVP) of sulfoxides containing β-hydrogen atoms affords sulfenic acids (RSOH) in good concentration under conditions where they are stable.The application of this technique to the synthesis and study of sterically hindered sulfenic acids 12a-e is described.The principal or primary reaction of simple sulfenic acids prepared in this manner is dehydration to thiosulfinates 13 (eq 1).Steric inhibition to dehydration (eq 1) appears to only be of importance for 2-methyl-2-propanesulfenic acid (12a) which was trapped in good yield with methyl propiolate to afford 16a. 2,4,6-Tri-tert-butylbenzenesulfenic acid (12e) appears to be destabilized as a consequence of interaction between the SOH and adjacent tert-butyl groups.In the pyrolysis section of the apparatus, 12e decomposes to phenol 21 and aryl radical 22, which reacts further.Thermolysis of sulfoxides generates the sulfenic acids 12a-e in very low concentration at any...

 https://www.lookchem.com/CASDataBase_1020-31-1.htm Some differences were observed in the solid- and liquid-phase benzylic oxidation of 2-(hydroxy- or dialkylamino)methyl-4,6-di-tert-butylphenols.Oxidation of these semi-hindered phenols with lead tetraacetate gave a new compound: 3,5-di-tert-butyl-ortho-benzoquinone diacylal.Keywords: semi-hindered phenols, synthesis, aldehyde, benzylic alcohol, oxidation, liquid phase, solid phase.

 https://www.lookchem.com/CASDataBase_10326-41-7.htm Rac-α-bromo acids, rac-4, have been converted into(R)- or(S)-α-hydroxy acids, (R)- or (S)-9 by DCC-induced esterification with the chiral auxiliaries (R)or (S)-1, followed by reaction with sodium p-methoxyphenoxide in the presence of tetra-n-hexylammonium iodide, conditions of dynamic kinetic resolution, to give quite diastereoselectively the (αR,3S)- or (αS,3R)-α-(p-methoxyphenoxy) esters, 7, which were then oxidized with eerie ammonium nitrate and hydrolyzed under controlled acid conditions.