Hexane → 2-t-Butyloxycarbonylamino-1-cyclohexylbut-3-ene

HRID 326383Notes

Reaction equation

C(=O)=O.CC(C)=O.[CH2:8]([Li])[CH2:9][CH2:10][CH3:11].[CH3:13][CH2:14][CH2:15][CH2:16][CH2:17][CH3:18].[C:19]([N:26](C1CCCCC1)[C@H](C=O)C)([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.O>[C:22]([O:21][C:19]([NH:26][CH:15]([CH:14]=[CH2:13])[CH2:16][CH:17]1[CH2:11][CH2:10][CH2:9][CH2:8][CH2:18]1)=[O:20])([CH3:25])([CH3:24])[CH3:23]

Participants

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 1.55M hexane solution) dropwise over the course of 5 min. After 10 min, the -78° C. bath was replaced with a 0° C. bath for 0.5 h, 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-cyclohexylalaninal (27.91 mmol) in anhydrous tetrahydrofuran (30 ml) over the course of 0.5 h. The mixture was then allowed to warm to room temperature during a 3 h 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. Chromatography with ether/hexane (1/9) provided the desired compound. Mass spectrum: (M+H)+ =254.

Workup

customthe -78° C. bath
customwas replaced with a 0° C.
customfor 0.5 h
additionwas added
extractionExtraction with hexane (4×100 ml)
customprovided a combined organic phase which
washwas washed with brine (100 ml)
dry with materialdried (Na2SO4)
concentrationconcentrated

Sources & evidence

ORD record: ord-ad28e9f0a0cc461dab290372e2411af2
Source dataset: uspto-grants-1993_12
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05268374

Reaction notes

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