p-Toluenesulfonic acid → 2-(2,6-Dimethylhepta-1,5-dien-1-yl)-4,5-dimethyl-1,3-dithiolane

Reaction equation

C1(C)C=CC(S(O)(=O)=O)=CC=1.[CH3:12][CH:13]([SH:17])[CH:14]([SH:16])[CH3:15].[CH3:18][C:19](=[CH:21][CH2:22][CH2:23][C:24](=[CH:26][CH:27]=O)[CH3:25])[CH3:20]>C1CCCCC1>[CH3:25][C:24]([CH2:23][CH2:22][CH:21]=[C:19]([CH3:20])[CH3:18])=[CH:26][CH:27]1[S:17][CH:13]([CH3:12])[CH:14]([CH3:15])[S:16]1

Participants

Procedure

Into a 100 ml reaction flask equipped with spin bar, reflux condenser, heating mantle and hot plate with magnetic stirring apparatus, is placed 0.5 grams para-toluenesulfonic acid, 5.0 ml cyclohexane and 6.1 grams (0.05 moles) of 2,3-butanedithiol. Over a period of 30 minutes with stirring is added to the reaction mass 7.6 grams (0.05 moles) of citral having the structure: ##STR23## After the citral is added, the reaction mass is heated to reflux and refluxed (with removal of water of reaction) over a period of 9 hours. At the end of the 9 hour period, the reaction mass is cooled and transferred to a separatory funnel. The reaction mass is then washed with one 50 ml portion of saturated sodium chloride solution and then dried over anhydrous sodium sulfate, filtered and distilled on a Microvigreux column yielding the following fractions: