ethyl 3-ethylsulfanylbutanoate

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Ethyl crotonate (commercially available, for example, from Aldrich) (2.37 g, 20.8 mmol) was dissolved in DMF (60 ml) and stirred at room temperature. Sodium ethanethiolate (commercially available, for example, from Aldrich) (1.66 g, 19.7 mmol) was added portionwise. On completion of the addition, the mixture was stirred at room temperature overnight. The mixture was diluted with water and extracted with EtOAc (×3). The combined organic solutions were dried (MgSO4), and concentrated in vacuo, for an extensive period of time to remove excess DMF. The residue was applied to a silica cartridge (50 g), eluting with a gradient of EtOAc-cyclohexane (2%-6%) to give the title compound as a colourless oil (527 mg, 14%): 1H NMR δ (CDCl3) 4.16 (2H, q, J=9 Hz), 3.28-3.18 (1H, m), 2.66-2.55 (3H, m), 2.44 (1H, dd, J=15, 8 Hz), 1.33 (3H, d, J=7 Hz), 1.31-1.23 (6H, m). On completion of the addition the mixture was stirred at room temperature overnight extracted with EtOAc (×3) The combined organic solutions were dried (MgSO4) concentrated in vacuo, for an extensive period of time to remove excess DMF eluting with a gradient of EtOAc-cyclohexane (2%-6%)