Isopropanol → (-) Ammonium(4S)-p-menth-1-ene-7-sulfonate

Reaction equation

C(O)(C)C.[CH3:5][C:6]1([CH3:14])[CH:12]2[CH2:13][CH:7]1[CH2:8][CH2:9][C:10]2=[CH2:11].[S:15](=[O:18])([OH:17])[O-:16].[NH4+:19]>O>[C:10]1([CH2:11][S:15]([O-:18])(=[O:17])=[O:16])[CH2:12][CH2:13][C@H:7]([CH:6]([CH3:14])[CH3:5])[CH2:8][CH:9]=1.[NH4+:19]

Participants

Procedure

Into a 1 liter flask equipped with magnetic stirrer were placed 450 ml isopropanol, 240 ml water and 54.4 grams (0.4 mole) β-pinene. Ammonium bisulfite, 105 grams (45%) was then added thereto. The mixture was stirred at 40°-45° C. for 22 hours. Thereafter, the solution was evaporated to dryness. Residue was extracted with methanol. The methanolic solution was filtered, and the resultant filtrate evaporated to dryness. Obtained were 84 grams product (85.8% purity; 77% yield).