经典的有机合成反应------Acid hydrolysis of an acetonide

rydberg

Acid hydrolysis of an acetonide; diols
SyntheticPage 125 (2001)
Submitted 23rd Aug 2001, published 23rd Aug 2001
zac etheridge (zac.etheridge@orange.net),
A contribution from the Caddick Group, Sussex
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Chemicals Used
15% HCl (2S)-4-Iodo-3-butyne-1,2-diol Methanol
Procedure
The acetonide (12.51g, 49.6mmol) is stirred in methanol (43mL) at room temperature and the HCl (4.3mL) is added. The reaction is stirred until completion (TLC, 7-8 hours) then carefully quenched with sodium bicarbonate solution, extracted 6 times with ether, washed with brine, dried over magnesium sulphate, filtered and concentrated in vacuum to give an off white solid. Purification can be by column chromatography eluting with 35-100% EtOAc/PE or more conveniently by recrystallisation using 1:1 EtOAc/PE to yield about 10g (90-95%) of white solid.
Author's Comments
This is a very simple and effective method for removal of acetonide groups. Recrystallising the product is easier than column chromatography as the compound takes some time to come off the columnn due to its polarity, and there is invariably a small amount of higher running impurity or starting material at the end.
Data
1H NMR (300MHz, CH3OD) 4.52 (1H, m), 3.66 (2H, m). M.P. 96C
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Lead Reference
Hirama M., Iguchi S., Xing G. J. Org. Chem. 2001, 66, 2146.