Hydrochloric Acid → Methyl (6Z)-7-hydroxy-7-(4-methylthiophenyl)-5-oxohept-6-enoate

Participants

Reaction Conditions

Reaction Steps

Lithium diisopropylamide mono(tetrahydrofuran) in cyclohexane (1.5 M; 28 mL, 42 mmol) was added to a solution of 1-(4-methylthiophenyl)ethan-1-one (5.16 g, 31 mmol) in THF (120 mL) and stirred for 30 minutes at −72° C. A solution of methyl 4-(chloroformyl)butyrate (1.78 g, 10.8 mmol) was added to the above solution and stirred for 30 minutes and then warmed slowly from the −72° C. to −45° C. To the reaction mixture was added 3N HCl (50 mL) and extracted with ethyl acetate (100 mL×3). The combined organic layers were washed with water, brine, dried over Na2SO4, filtered and evaporated. Trituration of the residue with diethyl ether/hexane gave a mixture of the title compound and starting material (˜30% yield) as a solid (2.42 g). The crude material was used in the next step without purification. A small quantity of pure sample was obtained at the beginning of the trituation. Mp. 92-93° C.

Provenance & Evidence