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

HRID 486867Notes

Reaction equation

HRID 486867 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-cyclotetradecatetraene-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-af998b4612974d1bae1ef6a7f32bcb01
Source dataset
uspto-grants-1994_03
Patent number
US05292911

Reaction notes

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