Réaction #80651

Équation de réaction

lithium perchlorate

methyl magnesium bromide

ether

H2SO4

4,4-dimethyl-6-bromo-2-oxo-thiochroman

Compound 31

4,4-dimethyl-6-bromo-2-oxo-thiochroman

→

title compound

4-Bromo-2-(1,1,3-trimethyl-3-hydroxybutyl) thiophenol

Conditions de réaction

Traitement

1. 1
   workup.ADDITIONThe above mixture was treated dropwise
2. 2
   Températurethe reaction mixture was then heated
3. 3
   Températureat reflux for 70 h
4. 4
   Températureto cool
5. 5
   AutreThe organic layer was separated
6. 6
   Extractionthe aqueous layer was extracted with 2×25 ml of ether
7. 7
   Lavagewashed successively with 2×25 ml of saturated NaHCO3 solution, 25 ml of water and 25 ml of saturated NaCl solution
8. 8
   Séchagedried (MgSO4)
9. 9
   AutreThe solvent was removed in-vacuo
10. 10
    Autrethe residue purified by flash chromatography

Mode opératoire

To 3.49 g (32.8 mmol) of lithium perchlorate was added under argon 35 ml of 3.0M (105 mmol) methyl magnesium bromide in ether. The above mixture was treated dropwise with stirring with a solution of 2.961 g (10.926 mmol) of 4,4-dimethyl-6-bromo-2-oxo-thiochroman (Compound 31) and the reaction mixture was then heated at reflux for 70 h. The reaction mixture was then allowed to cool and poured onto a mixture of 100 g of ice and 8 ml of conc. H2SO4. The organic layer was separated and the aqueous layer was extracted with 2×25 ml of ether. The organic layers were combined and washed successively with 2×25 ml of saturated NaHCO3 solution, 25 ml of water and 25 ml of saturated NaCl solution and then dried (MgSO4). The solvent was removed in-vacuo and the residue purified by flash chromatography to give the title compound as a pale yellow oil. PHR (CDCl3): & 1.05 (6H, s), 1.52 (6H, s), 2.30 (2H, s), 3.71 (1H, s), 7.22 (1H, dd, J-8.5 Hz, 2.1 Hz), 7.28 (1H, d, J-8.5 Hz), 7.35 (1H, d, J-2.1 Hz)

Source