Diisopropylamine → 2-(3-Benzyloxypropyl)-3-hydroxy-gamma-butyrolactone

Participants

Reaction Conditions

Reaction Steps

To a solution of 20.4 g (0.201 mole) of diisopropylamine in 250 ml of tetrahydrofurane is added dropwise 100.2 ml (0.201 mole) of 2.01M solution of n-butyllithium in hexane with stirring at 0° C. The solution is cooled to -78° C. and a solution of 40.56 g (0.182 mole) of ethyl 5-benzyloxypentanoate in 30 ml of tetrahydrofurane is added dropwise over a period of 1/2 h. The mixture is stirred at -78° C. for another 1/2 h and a solution of 33.5 g (0.192 mole) of t-butyldimethylsilyloxyacetaldehyde in 20 ml of tetrahydrofurane is added dropwise. The mixture is stirred at -78° C. for 1 h and 12.1 ml of acetic acid is added dropwise. The mixture is warmed to 0° C., diluted with 250 ml of ether and 250 ml of ethyl acetate and washed with water. The organic layer is evaporated, the residue is diluted with 322 ml of methanol and the solution is treated with 43.1 ml of concentrated hydrochloric acid with stirring for 20 h. The mixture is evaporated and the residue is extracted with ethyl acetate. The extracts are washed with water and brine, dried (MgSO4) and evaporated to give an oil which is then purified by flash chromatography using methylene chloride-ethyl acetate (4:1) as the eluent to obtain 2-(3-benzyloxy-propyl)-3-hydroxy-γ-butyrolactone as an oil.

Provenance & Evidence