Reaction #985306

Reaction equation

3,3-Diethoxy-1-propyne

Cyclopropanecarboxylic acid methoxy-methyl-amide

n-butyllithium

hexane

→

yellowish oil

Yield 43.7%

1-Cyclopropyl-4,4-diethoxy-but-2-yn-1-one

Yield 43.7%

Solvents

THF

Conditions

Workup

1. 1
   Temperatureto warm to −30° C.
2. 2
   Temperaturecooled again to −70° C
3. 3
   Otherrose to −50°
4. 4
   workup.STIRRINGthen stirred
5. 5
   Temperaturewithout cooling until 0° C.
6. 6
   Otherquenched with sat. NH4Cl solution (20 mL)
7. 7
   ExtractionExtraction
8. 8
   OtherThe crude brown oil (15 g) was purified by chromatography on silica gel in heptane/ethyl acetate 10:1

Procedure

3,3-Diethoxy-1-propyne (10 mL, 70 mmol) was dissolved under argon in THF (150 mL) and cooled to −70° C. Then a 1.6 M solution of n-butyllithium in hexane (48 mL, 77 mmol) was added slowly at −70° C., then allowed to warm to −30° C. and stirred at −30° C. for 30 min, then cooled again to −70° C. Cyclopropanecarboxylic acid methoxy-methyl-amide (10 g, 77 mmol) was added at once at −70° C. (the temperature rose to −50°) then stirred without cooling until 0° C. was reached, then quenched with sat. NH4Cl solution (20 mL). Extraction: 2×AcOEt, 1× sat. NH4Cl, 1× sat. NaCl. The crude brown oil (15 g) was purified by chromatography on silica gel in heptane/ethyl acetate 10:1. One obtained 6 g (43%) of a yellowish oil. MS: m/z=151(M).

Source