Sodium borohydride → (2S,5S)-1-tert-butyl 2-ethyl 5-hydroxypiperidine-1,2-dicarboxylate

HRID 2272845Notes

Reaction equation

[BH4-].[Na+].[O:3]=[C:4]1[CH2:9][N:8]([C:10]([O:12][C:13]([CH3:16])([CH3:15])[CH3:14])=[O:11])[C@H:7]([C:17]([O:19][CH2:20][CH3:21])=[O:18])[CH2:6][CH2:5]1>CCO>[OH:3][C@@H:4]1[CH2:9][N:8]([C:10]([O:12][C:13]([CH3:14])([CH3:15])[CH3:16])=[O:11])[C@H:7]([C:17]([O:19][CH2:20][CH3:21])=[O:18])[CH2:6][CH2:5]1

Participants

Conditions

Temperature: -40 °C

Procedure

NaBH4 (36 g, 1.0 mol) was added in portions to a solution of (S)-1-tert-butyl 2-ethyl 5-oxopiperidine-1,2-dicarboxylate (250 g, 0.92 mol) in EtOH (1500 mL) at −40° C. The reaction mixture was then stirred at −40° C. for 0.5 hr then quenched with 10% HOAc solution. After diluting with water, the mixture was extracted with DCM (3×). The combined organic layer was concentrated in vacuum and purified by silica gel column chromatography (1:1 petroleum ether/EtOAc) to afford (2S,5S)-1-tert-butyl 2-ethyl 5-hydroxypiperidine-1,2-dicarboxylate (205 g, 80%) as a yellow oil.

Workup

customthen quenched with 10% HOAc solution
additionAfter diluting with water
extractionthe mixture was extracted with DCM (3×)
concentrationThe combined organic layer was concentrated in vacuum
custompurified by silica gel column chromatography (1:1 petroleum ether/EtOAc)

Sources & evidence

ORD record: ord-3644135c264a495c9cf18205ef61a4b3
Source dataset: uspto-grants-2015_09
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09120795B2

Reaction notes

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