摘要 |
A method of making certain 2,3-dihydro-1,4-dithiins of the following formula by the action of alpha-hydroxyketones (acyloins) of 1,2-dithiols: <IMAGE> wherein R1 and R2 are hydrogen or alkyl having 1 to 6 carbon atoms or are joined together to form a ring with 3 or 4 methylene groups, and R3 and R4 are hydrogen or the same or different alkyl groups having 1 to 10 carbon atoms, which alkyl groups may be substituted with lower alkoxy groups. |