Reaction #5306

Reaction equation

2-Methoxypropene

2-bromo-1-[4-hydroxy-3-(hydroxymethyl)phenyl]ethanone

toluene-4-sulphonic acid

→

title compound

Yield 82.5%

2-Bromo-1-(2,2-dimethyl-1,3-benzodioxan-6-yl)ethanone

Yield 82.5%

Solvents

CH2Cl2

Conditions

Workup

1. 1
   Filtrationfiltered through a wad of triethylamine-deactivated silica
2. 2
   Otherevaporated
3. 3
   Otherto give an oil
4. 4
   OtherPurification by [FCTS] (300 g) [E]

Procedure

2-Methoxypropene (10 g) was added over 15 min to a stirred solution of 2-bromo-1-[4-hydroxy-3-(hydroxymethyl)phenyl]ethanone (5 g) and toluene-4-sulphonic acid (0.5 g) in CH2Cl2 (100 ml) at 23°. The mixture was stirred for 3h, filtered through a wad of triethylamine-deactivated silica and evaporated to give an oil. Purification by [FCTS] (300 g) [E] afforded the title compound as an oil (4.8 g) with solidified on cooling. A small sample was crystallised from light petroleum (b.p. 60-80°) to give white crystals m.p. 47-48°.

Source