反应 #2978

反应方程式

(3R,5S)-1-t-Butoxycarbonyl-5-carboxy-3-methylpyrrolidine-2-one

lithium hydroxide monohydrate

water

→

product

收率 99.0%

(2S,4R)-N-t-Butoxycarbonyl-4-methyl glutamic acid

收率 99.0%

溶剂

THF

THF

反应条件

后处理

1. 1
   其他was removed in vacuo and water (20 mL)
2. 2
   workup.ADDITIONwas added
3. 3
   workup.ADDITIONThe pH was adjusted to 3 by the addition of glacial acetic acid, ether (100 mL)
4. 4
   workup.ADDITIONwas added
5. 5
   其他the layers separated
6. 6
   萃取The aqueous phase was extracted with ether (3 x 100 mL)
7. 7
   洗涤the combined organic phases were washed with brine (400 mL)
8. 8
   干燥dried over Na2SO4
9. 9
   过滤filtered
10. 10
    其他evaporated to dryness
11. 11
    其他azeotroping with toluene (3 x 15 mL)
12. 12
    其他The residue was dried under high vacuum

实验过程

A solution of (3R,5S)-1-t-Butoxycarbonyl-5-carboxy-3-methylpyrrolidine-2-one (6.2 g, 25.5 mmol) in THF (50 mL) was treated with lithium hydroxide monohydrate (3 eq, 3.20 g) and water (5 mL). After stirring for 16 hr at room temperature the THF was removed in vacuo and water (20 mL) was added. The pH was adjusted to 3 by the addition of glacial acetic acid, ether (100 mL) was added and the layers separated. The aqueous phase was extracted with ether (3 x 100 mL) and the combined organic phases were washed with brine (400 mL), dried over Na2SO4, filtered and evaporated to dryness, azeotroping with toluene (3 x 15 mL). The residue was dried under high vacuum to give 6.58 g of the product (99%) as a white foam which was used without further purification: Rf 0.8 (1% formic acid in ethyl acetate, developed with ninhydrin). 1H NMR (200 MHz, D2O): δ 3.80 (dd, J=10.4, 4.7 Hz, 1H), 2.45 (m, 1H), 2.0 (m, 1H), 1.60 (ddd, J=12.8, 4.2, 10.3 Hz, 1H), 1.25 (s, 9H), 1.0 (d, J=7.0 Hz, 3H).

来源