Acetic Acid → tert-Butyl 9-hydroxy-3-azaspiro[5.5]undecane-3-carboxylate

HRID 1517370Notes

Reaction equation

[O:1]=[C:2]1[CH2:19][CH2:18][C:5]2([CH2:10][CH2:9][N:8]([C:11]([O:13][C:14]([CH3:17])([CH3:16])[CH3:15])=[O:12])[CH2:7][CH2:6]2)[CH2:4][CH2:3]1.[BH4-].[Na+].C(O)(=O)C>C1COCC1>[OH:1][CH:2]1[CH2:3][CH2:4][C:5]2([CH2:10][CH2:9][N:8]([C:11]([O:13][C:14]([CH3:15])([CH3:16])[CH3:17])=[O:12])[CH2:7][CH2:6]2)[CH2:18][CH2:19]1

Participants

Conditions

Temperature: -5 °C

Procedure

tert-Butyl 9-oxo-3-azaspiro[5.5]undecane-3-carboxylate (1.5 g) was dissolved in THF (7.5 ml) and the solution was cooled to −5° C. NaBH4 (0.212 g) was then added and the mixture was stirred at room temperature for 1 h (TLC control). When the reaction was complete, acetic acid was added to the mixture and the methanol was then distilled off. The residue was taken up in water (50 ml) and the mixture was extracted with ethyl acetate (2×50 ml). The combined organic phases were dried (Na2SO4) and concentrated in vacuo. The crude product obtained in this way was purified by column chromatography (silica gel, 30% ethyl acetate/hexane). Yield: 1.2 g (80%)

Workup

distillationthe methanol was then distilled off
extractionthe mixture was extracted with ethyl acetate (2×50 ml)
dry with materialThe combined organic phases were dried (Na2SO4)
concentrationconcentrated in vacuo

Sources & evidence

ORD record: ord-011db573c30e41d8bbe0adea4a6d5a43
Source dataset: uspto-grants-2012_07
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08232288B2

Reaction notes

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