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

Temperature

0 °C

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.

1. temperatureThe solution is cooled to -78° C.
2. stirringThe mixture is stirred at -78° C. for another 1/2 h
3. stirringThe mixture is stirred at -78° C. for 1 h
4. temperatureThe mixture is warmed to 0° C.
5. washwashed with water
6. customThe organic layer is evaporated
7. additionthe residue is diluted with 322 ml of methanol
8. additionthe solution is treated with 43.1 ml of concentrated hydrochloric acid
9. stirringwith stirring for 20 h
10. customThe mixture is evaporated
11. extractionthe residue is extracted with ethyl acetate
12. washThe extracts are washed with water and brine
13. dry with materialdried (MgSO4)
14. customevaporated
15. customto give an oil which
16. customis then purified by flash chromatography

ORD record

ord-ca5ef0c9512a4cb48385e3713567986c

Source dataset

uspto-grants-1994_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05371096