Reaction #2200581

Reaction equation

TEMPO

(2R,3S)-2-methyl-3-tetrahydropyranyloxybutanol

NaOCl

NaHCO3

sodium bromide

→

aldehyde

Yield 92.3%

(2S,3S)-2-methyl-3-tetrahydropyranyloxybutyraldehyde

Yield 92.3%

Solvents

toluene

EtOAc

H2O

Conditions

Workup

1. 1
   OtherThe aqueous phase was separated
2. 2
   Washwashed with Et2O (50 ml)
3. 3
   WashThe combined organic phases were washed with a KI solution (80 mg)
4. 4
   workup.DISSOLUTIONdissolved in aqueous 10% KHSO4 (20 ml)
5. 5
   Dryingwith a 10% aqueous sodium thiosulfate solution (10 ml), brine (20 ml), and dried (MgSO4)
6. 6
   FiltrationFiltration and concentration under vacuum

Procedure

An aqueous NaOCl solution (11 mmol, 5.3 ml of a 12.5% solution) and NaHCO3 (2.43 g, 29 mmol) was added dropwise, over a period of 1 hour, to a cold (0° C.), rapidly stirred (>1000 rpm), biphasic mixture consisting of (2R,3S)-2-methyl-3-tetrahydropyranyloxybutanol (5) (1.88 g, 10 mmol), TEMPO with free radicals (31.25 mg, 2%), sodium bromide (1.029 g, 10 mmol), toluene (30 ml), EtOAc (30 ml) and H2O (5 ml). The aqueous phase was separated and washed with Et2O (50 ml). The combined organic phases were washed with a KI solution (80 mg) dissolved in aqueous 10% KHSO4 (20 ml), and then with a 10% aqueous sodium thiosulfate solution (10 ml), brine (20 ml), and dried (MgSO4). Filtration and concentration under vacuum gave the desired aldehyde 6 (1.72 g, 92%) which was used for the next reactions without further purification.

Source