Reaktion #162205

Reaktionsgleichung

methyl cyclohexene-1-carboxylate

NH4Cl

N-isopropylpropan-2-amine

nBuLi

methyl iodide

HMPA

→

Methyl-1-methylcyclohex-2-ene-1-carboxylate

Lösungsmittel

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGAfter stirring an additional 10 min
2. 2
   Temperaturto warm to −5° C. over 2 h
3. 3
   WaschenAfter dilution with hexanes and washing with brine
4. 4
   Trocknenthe organic layer was dried over Na2SO4
5. 5
   Sonstigecarefully evaporated to 3.3 g of generate methyl 1-methylcyclohex-2-ene-1-carboxylate, 66a, which
6. 6
   Sonstigewas used without further purification

Vorschrift

To a cold (0° C.) solution of freshly distilled N-isopropylpropan-2-amine (4.20 mL, 29.96 mmol) in THF (150 mL) under argon was added dropwise nBuLi (12.65 mL of 2.2 M solution, 27.82 mmol). After 15 min the solution was cooled to −78° C. and dry HMPA (4.84 mL, 27.82 mmol) was added. The mixture was stirred for 30 min at −78° C. and methyl cyclohexene-1-carboxylate (3.00 g, 21.40 mmol) was then added. After stirring an additional 10 min, methyl iodide (2.00 mL, 32.10 mmol) was added. The solution was then allowed to warm to −5° C. over 2 h. An aqueous saturated solution of NH4Cl was poured into the orange mixture. After dilution with hexanes and washing with brine, the organic layer was dried over Na2SO4 and carefully evaporated to 3.3 g of generate methyl 1-methylcyclohex-2-ene-1-carboxylate, 66a, which was used without further purification.

Quelle