Trimethylaluminum → tert-butyl(2R,5R)-5-{[tert-butyl(dimethyl)silyl]oxy}-2-vinylpiperidine-1-carboxylate

HRID 255354Notes

Reaction equation

HRID 255354 reaction equation
[CH3:1][Al](C)C.[Si:5]([O:12][C@H:13]1[CH2:18][N:17]([C:19]([O:21][C:22]([CH3:25])([CH3:24])[CH3:23])=[O:20])[C@@H:16]([CH:26]=O)[CH2:15][CH2:14]1)([C:8]([CH3:11])([CH3:10])[CH3:9])([CH3:7])[CH3:6]>C1COCC1.ICI.C(OCC)(=O)C.[Zn]>[Si:5]([O:12][C@H:13]1[CH2:18][N:17]([C:19]([O:21][C:22]([CH3:24])([CH3:25])[CH3:23])=[O:20])[C@@H:16]([CH:26]=[CH2:1])[CH2:15][CH2:14]1)([C:8]([CH3:11])([CH3:9])[CH3:10])([CH3:6])[CH3:7]

Participants

7

Reactant 2

HCID 16682925TrimethylaluminumHCID 86630428tert-butyl(2R,5R)-5-{[tert-butyl(dimethyl)silyl]oxy}-2-formylpiperidine-1-carboxylate2×

Product 1

HCID 66774108tert-butyl(2R,5R)-5-{[tert-butyl(dimethyl)silyl]oxy}-2-vinylpiperidine-1-carboxylate

Reagents, catalysts & solvents 4

HCID 23994ZincCatalystHCID 6346DiiodomethaneSolventHCID 8028TetrahydrofuranSolvent2×HCID 8857Ethyl AcetateSolvent

Procedure

To a suspension of zinc dust (12.2 g) in THF (200 mL) and diiodomethane (5 mL) at 0° C. was added trimethylaluminium (2M in hexanes, 6 mL). After the addition the reaction was carefully warmed to room temperature (exothermic reaction!). The reaction was then cooled with an ice bath and a solution of tert-butyl (2R,5R)-5-{[tert-butyl(dimethyl)silyl]oxy}-2-formylpiperidine-1-carboxylate (Intermediate 189, 6.84 g) in THF (40 mL) was added. After 6 hours it was warmed to room temperature, the reaction was diluted with ethyl acetate and slowly quenched with a saturated aqueous solution of NaHCO3. The organic phase was collected and washed with NaHCO3 and brine, dried (Na2SO4), filtered and concentrated. Chromatography on silica gel with a gradient of 0-100% methylene chloride in hexanes gave 3.96 g of product.

Workup

  1. additionAfter the addition the reaction
  2. custom(exothermic reaction!)
  3. temperatureThe reaction was then cooled with an ice bath
  4. temperatureAfter 6 hours it was warmed to room temperature
  5. customslowly quenched with a saturated aqueous solution of NaHCO3
  6. customThe organic phase was collected
  7. washwashed with NaHCO3 and brine
  8. dry with materialdried (Na2SO4)
  9. filtrationfiltered
  10. concentrationconcentrated

Sources & evidence

ORD record
ord-8f4993e38ca74a7f8f4e59fb514c3187
Source dataset
uspto-grants-2011_01
Patent number
US07875715B2

Reaction notes

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