diethyl 2-ethyl-3-oxobutanedioate

Conditions: temp:-75.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 27.8 mL of lithium diisopropylamide (50.0 mmol, 1.00 eq, 1.8 M in THF/heptane/ethylbenzene) were dissolved in 50 mL of dry THF and an argon atmosphere and cooled to −75° C. 6.64 mL of ethyl butanoate (50.0 mmol, 1.00 eq) were dissolved in 25 mL of dry THF and added to the previous solution at a bath temperature of −60 to −75° C. and stirred for an additional 1 h at a bath temperature of −75° C. 6.92 mL of diethyl ethanedioate (51.0 mmol, 1.02 eq) were dissolved in 25 mL of dry THF and added to the previous solution at a bath temperature of −60 to −75° C. and stirred for an additional 30 min at a bath temperature of −75° C. The mixture was allowed to come to. −20° C., at which temperature 6.47 mL of acetic acid (113.0 mmol, 2.26 eq), followed by 100 mL of water. The mixture was then allowed to come to rt. The separated organic layer was washed, once with water, once with sodium bicarbonate solution and once with brine, before being dried over sodium sulfate and concentrated in vacuo. The crude reaction product was used for the next transformation without any further purification. added to the previous solution at a bath temperature of −60 to −75° C. added to the previous solution at a bath temperature of −60 to −75° C. stirred for an additional 30 min at a bath temperature of −75° C −20° C. to come to rt The separated organic layer was washed, once with water, once with sodium bicarbonate solution and once with brine before being dried over sodium sulfate concentrated in vacuo The crude reaction product was used for the next transformation without any further purification

Conditions: temp:-75.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 27.8 mL of lithium diisopropylamide (50.0 mmol, 1.00 eq, 1.8 M in THF/heptane/ethylbenzene) were dissolved in 50 mL of dry THF and an argon atmosphere and cooled to −75° C. 6.64 mL of ethyl butanoate (50.0 mmol, 1.00 eq) were dissolved in 25 mL of dry THF and added to the previous solution at a bath temperature of −60 to −75° C. and stirred for an additional 1 h at a bath temperature of −75° C. 6.92 mL of diethyl ethanedioate (51.0 mmol, 1.02 eq) were dissolved in 25 mL of dry THF and added to the previous solution at a bath temperature of −60 to −75° C. and stirred for an additional 30 min at a bath temperature of −75° C. The mixture was allowed to come to. −20° C., at which temperature 6.47 mL of acetic acid (113.0 mmol, 2.26 eq), followed by 100 mL of water. The mixture was then allowed to come to rt. The separated organic layer was washed, once with water, once with sodium bicarbonate solution and once with brine, before being dried over sodium sulfate and concentrated in vacuo. The crude reaction product was used for the next transformation without any further purification. added to the previous solution at a bath temperature of −60 to −75° C. added to the previous solution at a bath temperature of −60 to −75° C. stirred for an additional 30 min at a bath temperature of −75° C −20° C. to come to rt The separated organic layer was washed, once with water, once with sodium bicarbonate solution and once with brine before being dried over sodium sulfate concentrated in vacuo The crude reaction product was used for the next transformation without any further purification