β,γ-efoxy sulfones in organic synthesis. Part 2: Preparation of β,γ-bifunctionalized sulfones
作者:Carmen Nájera、José M. Sansano
DOI:10.1016/s0040-4020(01)87131-3
日期:1991.1
Heteronucleophiles reagents react with beta,gamma-epoxy sulfones 1 at the gamma-position in the presence of Ti(OPr(i))4 or magnesium halides to afford regioselectively gamma-functionalized beta-hydroxy sulfones 2. With soft nucleofiles such as sodium azide, triphenylphosphine, or sodium benzethiolate the reaction takes place in the absence of Lewis acids. In the case of basic reagents such as sodium methoxide or diethylamine the corresponding regioisomers, the beta-functionalized gamma-hydroxy sulfones 3 were exclusively obtained. The preparation of compounds 3 (R2 = H) was also carried out starting from 3-tosyl-2-propen-1-ol (4) by Micheal addition of different heteronucleophiles.
Simple Synthesis of <font>β</font>-Acetoxy Thiocyanates from Oxiranes
作者:Edyta Łukowska-Chojnacka、Jan Plenkiewicz
DOI:10.1080/00397911.2010.494817
日期:2011.7.1
Abstract A convenient and simple method for the preparation of previously unknown β-acetoxy thiocyanates by regioselective ringopening of the corresponding oxiranes with thiocyanate anion followed by acetylation is described. The shorter reaction times, better yields of the products, and easy workup are the advantages of this methodology.