Methyl vinyl ketone → Tert-butyl 9-oxo-3-azaspiro[5.5]undec-7-ene-3-carboxylate

HRID 2059914Notes

Reaction equation

[CH:1]([CH:3]1[CH2:8][CH2:7][N:6]([C:9]([O:11][C:12]([CH3:15])([CH3:14])[CH3:13])=[O:10])[CH2:5][CH2:4]1)=O.[CH:16]([C:18]([CH3:20])=[O:19])=[CH2:17].[OH-].[K+]>C1COCC1.C(O)C>[O:19]=[C:18]1[CH2:16][CH2:17][C:3]2([CH2:8][CH2:7][N:6]([C:9]([O:11][C:12]([CH3:15])([CH3:14])[CH3:13])=[O:10])[CH2:5][CH2:4]2)[CH:1]=[CH:20]1

Participants

Conditions

Temperature: 25 °C

Procedure

To the solution of tert-butyl 4-formylpiperidine-1-carboxylate (5.87 mmol, 1 eq) in THF (250 ml) was added methyl vinyl ketone (7.63 mmol, 1.3 eq) at 0° C., followed by slow addition of 3 N KOH in ethanol (7.7 ml). The reaction was then stirred at 25° C. for 16 h. The reaction mixture was concentrated to one-third of the volume of solvent and then acidified with 0.5 N HCl at 0° C. The aqueous layer was extracted with ethyl acetate (2×100 ml), and the organics dried over Na2SO4 and concentrated. The crude material was used in the next step without further purification. Yield: 91%

Workup

concentrationThe reaction mixture was concentrated to one-third of the volume of solvent
customacidified with 0.5 N HCl at 0° C
extractionThe aqueous layer was extracted with ethyl acetate (2×100 ml)
dry with materialthe organics dried over Na2SO4
concentrationconcentrated
customThe crude material was used in the next step without further purification

Sources & evidence

ORD record: ord-98b505bb3c7f47f085dac2d6cad34a42
Source dataset: uspto-grants-2012_10
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08278319B2

Reaction notes

Loading…