Cerium(III) chloride → (S)-tert-butyl (2,2,3,3,11,11,12,12-octamethyl-7-methylene-4,10-dioxa-3,11-disilatridecan-6-yl)(2-oxopent-3-en-1-yl)carbamate

HRID 627282Notes

Reaction equation

HRID 627282 reaction equation
[Cl-].[Ce+3].[Cl-].[Cl-].[CH:5](/[Mg]Br)=[CH:6]\[CH3:7].CON(C)[C:13](=[O:45])[CH2:14][N:15]([C@@H:23]([C:33](=[CH2:44])[CH2:34][CH2:35][O:36][Si:37]([CH3:43])([CH3:42])[C:38]([CH3:41])([CH3:40])[CH3:39])[CH2:24][O:25][Si:26]([CH3:32])([CH3:31])[C:27]([CH3:30])([CH3:29])[CH3:28])[C:16](=[O:22])[O:17][C:18]([CH3:21])([CH3:20])[CH3:19]>C1COCC1>[CH3:28][C:27]([CH3:30])([Si:26]([CH3:31])([CH3:32])[O:25][CH2:24][C@@H:23]([N:15]([CH2:14][C:13](=[O:45])[CH:5]=[CH:6][CH3:7])[C:16](=[O:22])[O:17][C:18]([CH3:21])([CH3:20])[CH3:19])[C:33](=[CH2:44])[CH2:34][CH2:35][O:36][Si:37]([CH3:42])([CH3:43])[C:38]([CH3:39])([CH3:40])[CH3:41])[CH3:29]

Participants

5

Reactant 3

HCID 24636Cerium(III) chlorideHCID 131735299(5)-Tert-butyl (2-(methoxy(methyl)amino)-2-oxoethyl)(2,2,3,3,11,11,12,12-octamethyl-7-methylene-4,10-dioxa-3,11-disilatridecan-6-yl)carbamate2×HCID 178456052HCID 178456052, compound

Product 1

HCID 131735301(S)-tert-butyl (2,2,3,3,11,11,12,12-octamethyl-7-methylene-4,10-dioxa-3,11-disilatridecan-6-yl)(2-oxopent-3-en-1-yl)carbamateYield 76.4%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Conditions

Temperature
-78 °C

Procedure

A suspension of cerium (III) chloride (47.6 g, 193.26 mmol) in THF (200 mL) 3 at room temperature was stirred vigorously for 2 hours. The suspension was cooled to −78° C. and (E)-prop-1-enylmagnesium bromide (0.5 M in THF) (387 mL, 193.26 mmol) was added dropwise. The mixture was stirred at −78° C. for 1.5 hours. (5)-tert-butyl (2-(methoxy(methyl)amino)-2-oxoethyl)(2,2,3,3,11,11,12,12-octamethyl-7-methylene-4,10-dioxa-3,11-disilatridecan-6-yl)carbamate (Intermediate 278, 13.55 g, 24.16 mmol) in THF (50 mL) was then added dropwise at −78° C. The reaction was stirred at −78° C. for 1 hour and then warmed to 0° C. for 30 minutes. The reaction was quenched with 10% citric acid, diluted further with water and extracted twice with ether. The organics were dried over magnesium sulfate, filtered and concentrated. Silica gel chromatography (0%-20% ethyl acetate/hexanes) afforded the title compound (10 g, 76%) as a yellow oil.

Workup

  1. stirringThe mixture was stirred at −78° C. for 1.5 hours
  2. stirringThe reaction was stirred at −78° C. for 1 hour
  3. temperaturewarmed to 0° C. for 30 minutes
  4. customThe reaction was quenched with 10% citric acid
  5. additiondiluted further with water
  6. extractionextracted twice with ether
  7. dry with materialThe organics were dried over magnesium sulfate
  8. filtrationfiltered
  9. concentrationconcentrated

Sources & evidence

ORD record
ord-fdcc797ac4964967af4f88f45523e793
Source dataset
uspto-grants-2016_04
Patent number
US09309245B2

Reaction notes

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