HCID 12971708, compound → 6-Bromo-8-vinyl-2,2,4,4-tetramethyl-chroman

HRID 381045Notes

Reaction equation

HRID 381045 reaction equation
[CH2:1](OC(=O)C1C=CC(C#CC2C=CC3C(NC4CC4)CCC(C)(C)C=3C=2)=CC=1)C.[Br:30][C:31]1[CH:32]=[C:33]2[C:38](=[C:39]([CH:41]=O)[CH:40]=1)[O:37][C:36]([CH3:44])([CH3:43])[CH2:35][C:34]2([CH3:46])[CH3:45]>CCCCCC>[Br:30][C:31]1[CH:32]=[C:33]2[C:38](=[C:39]([CH:41]=[CH2:1])[CH:40]=1)[O:37][C:36]([CH3:44])([CH3:43])[CH2:35][C:34]2([CH3:46])[CH3:45]

Participants

4

Reactant 2

HCID 12971708HCID 12971708, compound2×HCID 225689466-Bromo-2,2,4,4-tetramethyl chroman-8-carbaldehyde2×

Product 1

HCID 225689226-Bromo-8-vinyl-2,2,4,4-tetramethyl-chromanYield 72%

Reagents, catalysts & solvents 1

HCID 8058HexaneSolvent

Procedure

A solution of methylidene triphenyl phosphorane [generated from methyl triphenylphosphonium bromide (7 g, 20 mmol) and (11.8 mL, 19 mmol) of a 1 .6M solution of n-butyl lithium in hexanes] was added 6-bromo-2,2,4,4-tetramethyl chroman-8-carbaldehyde (Intermediate 30, 0.52 g, 1.75 mmol). After 1 h the reaction mixture was diluted with hexane, washed with brine (×1), dried over anhydrous sodium sulfate, filtered and evaporated in vacuo to a clear oil which was subjected to flash column chromatography over silica gel (230-400 mesh) using 2% ethyl acetate in hexane as the eluent to afford the title compound as a clear oil (0.37 g, 72%).

Workup

  1. washwashed with brine (×1)
  2. dry with materialdried over anhydrous sodium sulfate
  3. filtrationfiltered
  4. customevaporated in vacuo to a clear oil which

Sources & evidence

ORD record
ord-569bd1803482404f9f8d5e5557063fa1
Source dataset
uspto-grants-2001_10
Patent number
US06303785B1

Reaction notes

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