Ethyl Acetoacetate → HCID 131711958, compound

HRID 1732259Notes

Reaction equation

[O:1]([CH2:19][CH:20]([CH3:29])[CH2:21][CH2:22][CH2:23][C:24](C)(O)[CH:25]=C)[Si:2]([C:15]([CH3:18])([CH3:17])[CH3:16])([C:9]1[CH:14]=[CH:13][CH:12]=[CH:11][CH:10]=1)[C:3]1[CH:8]=[CH:7][CH:6]=[CH:5][CH:4]=1.[C:30]([O:36]CC)(=O)[CH2:31][C:32]([CH3:34])=O.[C:39]([O-])(=O)C.[Na+]>>[O:1]([CH2:19][CH:20]([CH3:29])[CH2:21][CH2:22][CH2:23]/[C:24](/[CH3:25])=[CH:34]\[CH2:32][CH2:31][C:30](=[O:36])[CH3:39])[Si:2]([C:15]([CH3:16])([CH3:17])[CH3:18])([C:9]1[CH:10]=[CH:11][CH:12]=[CH:13][CH:14]=1)[C:3]1[CH:8]=[CH:7][CH:6]=[CH:5][CH:4]=1

Participants

Reactant 3

HCID 8868Ethyl Acetoacetate

HCID 517045Sodium Acetate

HCID 20305779HCID 20305779, compound

Product 1

HCID 131711958HCID 131711958, compoundYield 50%

Conditions

Temperature: 205 °C

Procedure

8-t-Butyldiphenylsiloxy-3,7-dimethyl-1-octen-3-ol (60.33 g) is treated with ethyl acetoacetate (28.8 ml) and anhydrous sodium acetate (232 mg) and the mixture is allowed to stir for 2 hours at 205° C. under a short path distillation head to remove the ethanol formed in the reaction. The crude reaction mixture is purified via silica gel chromatography using ethyl acetate-hexane gradients to give 6 E/Z-1-t-butyldiphenylsiloxy-2,6-dimethyl-10-oxo-undec-6 -ene (32.9 g, 50%) as a yellow oil: ir (neat) 5.8μ (C=O); nmr (CDCl3)δ0.9 (d, CH3CH<), 1.05 [s, (CH3)3C], ##STR7## 2.08 ##STR8## 3.48 (d, 2H, OCH2CH<), 5.03 (b, 1H, C=CH--), 7.17-7.8 (m, 10 H, 2φ); m.s., M+ 450 (parent peak) not observed but M-57 (t-Bu) 393 present. A mixture of 60/40 E/Z isomers is observed by gas chromatography.

Workup

customto remove the ethanol
customformed in the reaction
customThe crude reaction mixture
customis purified via silica gel chromatography

Sources & evidence

ORD record: ord-59c65514e80340919a833688a638755f
Source dataset: uspto-grants-1980_12
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US04237055

Reaction notes

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