Isobutyraldehyde → (1S,4aS,8aR)-tert-Butyl-(5-ethylidene-4a-methyl-decahydro-naphtalen-1-yloxy)-dimethyl-silane

HRID 1075552Notes

Reaction equation

HRID 1075552 reaction equation
[C:1]([Si:5]([CH3:20])([CH3:19])[O:6][C@H:7]1[CH2:16][CH2:15][CH2:14][C@@:13]2([CH3:17])[C@H:8]1[CH2:9][CH2:10][CH2:11][C:12]2=O)([CH3:4])([CH3:3])[CH3:2].[CH:21](=O)[CH:22](C)C>[Br-].C([P+](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1)C.O1CCCC1.C(OCC)C>[C:1]([Si:5]([O:6][C@@H:7]1[C@H:8]2[C@@:13]([CH3:17])([C:12](=[CH:21][CH3:22])[CH2:11][CH2:10][CH2:9]2)[CH2:14][CH2:15][CH2:16]1)([CH3:20])[CH3:19])([CH3:4])([CH3:3])[CH3:2]

Participants

6

Reactant 2

HCID 6561IsobutyraldehydeHCID 21309364(4aR,5S,8aS)-5-(tert-Butyl-dimethyl-silanyloxy)-8a-methyl-octahydro-naphtalen-1-one

Product 1

HCID 57178905(1S,4aS,8aR)-tert-Butyl-(5-ethylidene-4a-methyl-decahydro-naphtalen-1-yloxy)-dimethyl-silaneYield 95%

Reagents, catalysts & solvents 3

HCID 73727Phosphonium, ethyltriphenyl-, bromide (1:1)Catalyst2×HCID 3283Diethyl EtherSolventHCID 8028TetrahydrofuranSolvent3×

Procedure

A suspension of 11.8 g (31.7 mMol) of ethyltriphenylphosphoniumbromide in 64 ml of tetrahydrofuran is treated under stirring and argon atmosphere with 31.9 ml of a one molar solution of potassiumtertiobutylate and the resulting orange suspension treated with a solution of 3.17 g (10.7 mMol) of (4aR,5S,8aS)-5-(tert-Butyl-dimethyl-silanyloxy)-8a-methyl-octahydro-naphtalen-1-one in 64 ml of tetrahydrofuran and kept at room temperature for 3 hours. An additional 11.8 g (31.7 mMol) of ethyltriphenylphosphoniumbromid and 31.9 ml of a one molar solution of potassiumtertiobutylate in tetrahydrofurane are added and the reaction mixture kept overnight. Isobutyraldehyde (5.4 ml) is added, the reaction is stirred for 10 minutes, diluted with diethylether and filtered over Florisil using diethylether as eluent. After evaporation in vacuo, the residue (4.79 g) is chromatographed over 120 g of silica gel with hexane to yield 3.15 g (95%) of pure (1S,4aS,8aR)-tert-Butyl-(5-ethylidene-4a-methyl-decahydro-naphtalen-1-yloxy)-dimethyl-silane (E/Z 4/1) as an oil.

Workup

  1. additionis treated
  2. waitthe reaction mixture kept overnight
  3. stirringthe reaction is stirred for 10 minutes
  4. filtrationfiltered over Florisil
  5. customAfter evaporation in vacuo
  6. customthe residue (4.79 g) is chromatographed over 120 g of silica gel with hexane

Sources & evidence

ORD record
ord-50326dabcc4e4cbc885572aee04756d7
Source dataset
uspto-grants-1999_05
Patent number
US05905074

Reaction notes

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