反应详情

To a solution of pent-4-ynal (6.99 g, 85.1 mmol) dissolved in methylene chloride (85 mL) was added 1,3-propanedithiol (8.54 mL, 85.1 mmol). The solution was stirred at room temperature for 1 hour and then cooled to -20° C. Boron trifluoride etherate (10.46 mL, 85.1 mmol) was added and, after warming to room temperature, the solution was stirred for 16 hours. The solution was washed with water (2×20 mL) and the aqueous extract was washed with additional methylene chloride (2×40 mL). The combined organic extracts were washed with 10% potassium hydroxide solution (4×30 mL) and the aqueous extract was washed with additional methylene chloride (2×40 mL). The combined organic extracts were washed with 10% potassium hydroxide solution (4×30 mL) and the aqueous extract was back-extracted with methylene chloride (2×40 mL). The combined organic extracts were washed with brine (2×40 mL) and dried (K2CO3). The solvent was removed by rotary evaporation to afford 9.14 g (62%) of 2-(but-3-ynyl)-1,3-dithiane as a pale yellow oil. 1H NMR (CDCl3)δ: 4.2 (t, 1H), 3.1-2.8 (m, 4H), 2.6-2.4 (m, 1H), 2.3-2.0 (m, 6H); IR (neat): 3286, 2908, 1421, 1272, 907 cm-1 ; GC retention time=3.11 min (88% area); TLC (silica gel, 90% hexane: 10% ethyl acetate) Rf=0.74.

1. temperaturecooled to -20° C
2. temperatureafter warming to room temperature
3. stirringthe solution was stirred for 16 hours
4. washThe solution was washed with water (2×20 mL)
5. extractionthe aqueous extract
6. washwas washed with additional methylene chloride (2×40 mL)
7. washThe combined organic extracts were washed with 10% potassium hydroxide solution (4×30 mL)
8. extractionthe aqueous extract
9. washwas washed with additional methylene chloride (2×40 mL)
10. washThe combined organic extracts were washed with 10% potassium hydroxide solution (4×30 mL)
11. extractionthe aqueous extract
12. extractionwas back-extracted with methylene chloride (2×40 mL)
13. washThe combined organic extracts were washed with brine (2×40 mL)
14. dry with materialdried (K2CO3)
15. customThe solvent was removed by rotary evaporation