反应详情

Into a mixture consisting of 10 g of maleic acid anhydride, 8.5 g of 2-hydroxy-2-methylheptane-1-thiol and 105 ml of methylene chloride, 1 ml of diisopropylamine, dissolved in 5 ml of methylene chloride is dropped. During this step the temperature is maintained at equal to or less than 30°. An additional 8.5 g of 2-hydroxy-2-methylheptane-1-thiol, dissolved in 5 ml of methylene chloride is added. After 15 minutes the usual work-up is performed. (Usual working up refers to the following procedure throughout the examples: washing of the organic phase with 1% aqueous sulphuric acid and with water; drying of the organic phase over MgSO4 ; distilling off the solvent; and chromatographic purification of the residue on silica gel with chloroform or ether:petroleum ether = 2:8 as elution agent.) 6-pentyl-6-methyl-2-oxo-1,4-oxathiane-3-acetic acid is obtained: NMR: 3.88 (q), 1.54 (s), 0.9 (t).

1. additionis dropped
2. temperatureDuring this step the temperature is maintained at equal to or less than 30°
3. additionis added
4. washwashing of the organic phase with 1% aqueous sulphuric acid and with water
5. dry with materialdrying of the organic phase over MgSO4
6. distillationdistilling off the solvent
7. customand chromatographic purification of the residue on silica gel with chloroform or ether
8. washpetroleum ether = 2:8 as elution agent