Hexane → tert-butyl N-(5-methylhex-1-en-3-yl)carbamate

HRID 1722670Notes

Reaction equation

HRID 1722670 reaction equation
[C:1](=O)=O.CC(C)=O.C([Li])CCC.CCCCCC.[C:19]([NH:26][C@H:27]([CH:32]=O)[CH2:28][CH:29]([CH3:31])[CH3:30])([O:21][C:22]([CH3:25])([CH3:24])[CH3:23])=[O:20]>[Br-].C[P+](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1.O1CCCC1.CCOCC.CCCCCC.O>[C:22]([O:21][C:19]([NH:26][CH:27]([CH2:28][CH:29]([CH3:31])[CH3:30])[CH:32]=[CH2:1])=[O:20])([CH3:25])([CH3:24])[CH3:23]

Participants

9

Reactant 4

HCID 8058HexaneHCID 104275tert-butyl N-[(2S)-4-methyl-1-oxopentan-2-yl]carbamateHCID 18522661Acetone cardiceHCID 178418339Butyllithium

Product 1

HCID 13985400tert-butyl N-(5-methylhex-1-en-3-yl)carbamateYield 60%

Reagents, catalysts & solvents 4

HCID 74505Methyltriphenyliphosphonium bromideCatalystHCID 962WaterSolventHCID 8028TetrahydrofuranSolvent2×HCID 21584099Diethylether hexaneSolvent

Conditions

Temperature
-78 °C

Procedure

To a stirred suspension of methyltriphenyl phosphonium bromide (10.97 g, 30.70 mmol) in anhydrous tetrahydrofuran (200 mL) at -78° C. (dry ice/acetone bath) under an argon atmosphere, was added n-butyl lithium, (19.8 mL of a 1.55 M hexane solution) dropwise over the course of 5 minutes. After 10 minutes, the -78° C. bath was replaced with a 0° C. bath for one-half hour, at which time the resulting orange solution was cooled again to -78° C. The solution was then added dropwise by cannula to a stirred -78° C. solution of Boc-leucinal (6.00 g, 27.91 mmol) in anhydrous tetrahydrofuran (30 mL) over the course of one-half hour. The mixture was then allowed to warm to room temperature during a 3 hour period after which water (150 mL) was added. Extraction with hexane (4×100 mL) provided a combined organic phase which was washed with brine (100 mL), dried (Na2SO4 ), and concentrated to give crude 3-t-butyloxycarbonylamino-5-methylhex-1-ene (6.5 g). Chromatography with ether/hexane (1/9) provided pure 3-t-butyloxycarbonylamino-5-methylhex-1-ene (3.71 g, 60%). Mass spectrum: EI, M+ -57=156; CI, (M+H)30 =214.

Workup

  1. customdropwise over the course of 5 minutes
  2. customthe -78° C. bath
  3. customwas replaced with a 0° C.
  4. customfor one-half hour
  5. additionwas added
  6. extractionExtraction with hexane (4×100 mL)
  7. customprovided a combined organic phase which
  8. washwas washed with brine (100 mL)
  9. dry with materialdried (Na2SO4 )
  10. concentrationconcentrated
  11. customto give crude 3-t-butyloxycarbonylamino-5-methylhex-1-ene (6.5 g)

Sources & evidence

ORD record
ord-032e612690aa4162aa58f76ada696c59
Source dataset
uspto-grants-1989_08
Patent number
US04857507

Reaction notes

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