Reaction equation
C[Si](C)(C)[CH:3]1[S:8][CH2:7][CH2:6][CH2:5][S:4]1.[Li]CCCC.[CH2:16]([CH:19]1[CH2:24][CH2:23][CH:22]([CH:25]2[CH2:32][C:27]3([CH2:30][C:29](=O)[CH2:28]3)[CH2:26]2)[CH2:21][CH2:20]1)[CH2:17][CH3:18]>C1COCC1>[CH2:16]([CH:19]1[CH2:20][CH2:21][CH:22]([CH:25]2[CH2:32][C:27]3([CH2:30][C:29](=[C:3]4[S:8][CH2:7][CH2:6][CH2:5][S:4]4)[CH2:28]3)[CH2:26]2)[CH2:23][CH2:24]1)[CH2:17][CH3:18]Participants
Conditions
- Temperature
- -70 °C
Procedure
15.5 g (80.3 mmol) of 2-trimethylsilyl-1,3-dithiane are dissolved in 150 ml of THF, and 51 ml (80.3 mmol) of n-BuLi (15 percent in hexane) are rapidly added dropwise at −70° C. The batch is subsequently allowed to thaw to 0° C. over the course of 4 hours, stirred for 10 minutes without cooling and re-cooled to −70° C., and a solution of 17.0 g (72.5 mmol) of 6-(4-n-propylcyclohexyl)spiro[3.3]heptan-2-one 5 in 50 ml of THF is added drop-wise. The batch is left to stir overnight at room temperature, hydrolysed using saturated sodium hydrogencarbonate solution and extracted with dichloromethane. The combined organic phases are washed with water and dried over sodium sulfate. The solvent is removed under reduced pressure, and the crude product is recrystallised from n-heptane. The dithioacetal 6 is obtained as colourless flakes.
Workup
- customthaw to 0° C.
- customover the course of 4 hours
- temperaturewithout cooling
- waitThe batch is left
- stirringto stir overnight at room temperature
- extractionhydrolysed using saturated sodium hydrogencarbonate solution and extracted with dichloromethane
- washThe combined organic phases are washed with water
- dry with materialdried over sodium sulfate
- customThe solvent is removed under reduced pressure
- customthe crude product is recrystallised from n-heptane
Sources & evidence
- ORD record
- ord-02150b853006410f8c6b73682c2e4987
- Source dataset
- uspto-grants-2007_09
- Patent number
- US07270856B2
Linked notes
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