Lithium Hexamethyldisilazide → 2-(1-Methylethyl)-5,9,13-trimethyl-1-trimethylsiloxy-2,4,8,12-cyclotetradecatetraene-1-carbonitrile

HRID 892642Notes

Reaction equation

HRID 892642 reaction equation
C[Si]([N-][Si](C)(C)C)(C)C.[Li+].Cl[CH2:12][C:13]([CH3:38])=[CH:14][CH2:15][CH2:16][C:17]([CH3:37])=[CH:18][CH2:19][CH2:20][C:21]([CH3:36])=[CH:22][CH:23]=[C:24]([CH:33]([CH3:35])[CH3:34])[CH:25]([O:28][Si:29]([CH3:32])([CH3:31])[CH3:30])[C:26]#[N:27]>O1CCCC1>[CH3:34][CH:33]([C:24]1[C:25]([O:28][Si:29]([CH3:32])([CH3:31])[CH3:30])([C:26]#[N:27])[CH2:12][C:13]([CH3:38])=[CH:14][CH2:15][CH2:16][C:17]([CH3:37])=[CH:18][CH2:19][CH2:20][C:21]([CH3:36])=[CH:22][CH:23]=1)[CH3:35].[CH3:35][CH:33]([C:24]1[C:25](=[O:28])[CH2:26][C:13]([CH3:38])=[CH:14][CH2:15][CH2:16][C:17]([CH3:37])=[CH:18][CH2:19][CH2:20][C:21]([CH3:36])=[CH:22][CH:23]=1)[CH3:34]

Participants

5

Reactant 2

HCID 2733832Lithium HexamethyldisilazideHCID 53993800HCID 53993800, compound

Product 2

HCID 544770112-(1-Methylethyl)-5,9,13-trimethyl-1-trimethylsiloxy-2,4,8,12-cyclotetradecatetraene-1-carbonitrileYield 83%HCID 570081642-(1-Methylethyl)-5,9,13-trimethyl-2,4,8,12-cyclotetradecatetraen-1-oneYield 16%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

A solution of lithium bis(trimethylsilyl) amide (5.0 mmol, 0.25 M) in dry tetrahydrofuran (20 ml) is stirred under argon atmosphere on an oil bath at 40° C. and thereto is dropwise added a solution of the cyanohydrin trimethylsilyl ether which is 15-chloro-3-(1-methylethyl)-6,10,14-tri-methyl-2-trimethylsiloxy-3,5,9,13-pentadecatetraenenitrile (378 mg, 0.895 mmol) prepared in Reference Example 5 in dry tetrahydrofuran (15 ml) over 50 minutes. After stirring the mixture at this temperature for 20 minutes, the reaction is quenched by adding a saturated aqueous ammonium chloride solution while stirring on an ice-water bath. After removing tetrahydrofuran by distillation under reduced pressure, the organic layer is extracted with ether. The obtained extract is purified by silica gel column chromatography (n-hexane/ethyl acetate =60:1) to give 2-(1-methylethyl)-5,9,13-trimethyl-1-trimethylsiloxy-2,4,8,12-cyclotetradecatetraene-1-carbonitrile (288 mg, 83%) and 2-(1-methylethyl)-5,9,13-trimethyl-2,4,8,12-cyclotetradeca-tetraen-1-on (42.9 mg, 16%).

Workup

  1. customthe reaction is quenched
  2. additionby adding a saturated aqueous ammonium chloride solution
  3. stirringwhile stirring on an ice-water bath
  4. customAfter removing tetrahydrofuran
  5. distillationby distillation under reduced pressure
  6. extractionthe organic layer is extracted with ether
  7. extractionThe obtained extract
  8. customis purified by silica gel column chromatography (n-hexane/ethyl acetate =60:1)

Sources & evidence

ORD record
ord-fe6ca8b7887141968dc6c3f5dec18cc9
Source dataset
uspto-grants-1992_06
Patent number
US05118827

Reaction notes

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