Reaction equation
[C:1]([N:11]1[CH2:17][CH2:16][CH2:15][C@H:12]1[CH2:13][OH:14])([O:3][CH2:4][C:5]1[CH:10]=[CH:9][CH:8]=[CH:7][CH:6]=1)=[O:2].[Na+].[Br-].CC1(C)N([O])C(C)(C)CCC1.C([O-])([O-])=O.[Na+].[Na+].[O-]Cl.[Na+]>C1(C)C=CC=CC=1.O>[C:1]([N:11]1[CH2:17][CH2:16][CH2:15][C@H:12]1[CH:13]=[O:14])([O:3][CH2:4][C:5]1[CH:10]=[CH:9][CH:8]=[CH:7][CH:6]=1)=[O:2]Participants
Conditions
- Temperature
- 0 °C
Procedure
Following the method of Leanna et al. (M. Robert Leanna, Thomas J. Sowin, Howard E. Morton, Tetrahedron Lett., 1992, 33(35), 5029-5032), carbobenzyloxy-L-prolinol (9.23 g, 39 mmole) in toluene (100 mL) at 0° C. was added NaBr (Aldrich, 4.01 g, 40 mmole) in water (45 mL) followed by 2,2,6,6-tetramethyl-1-piperidinyloxy free radical (TEMPO reagent, Aldrich, 0.05 g, 0.32 mmole). To this vigorously-stirred mixture was added a mixture of Na2CO3 (11.16 g, 132 mmole)in water (50 mL) and aqueous NaOCl (0.7M, 65 mL, 46 mmole) dropwise over 30 minutes. After stirring 30 minutes at 0° C. the mixture was extracted with ethyl acetate (2×250 mL). The combined organics were washed with Kl 5% KHSO4 (1×50 mL), then aqueous Na2S2O3 (1×100 mL), then pH 7 phosphate buffer (1×100 mL), then brine (1×100 mL) and dried (Na2SO4). Filtration and evaporation of solvents left carbobenzyloxy-L-prolinal (5.55 g) as an oil.
Workup
- customat 0° C.
- additionTo this vigorously-stirred mixture was added
- extractionwas extracted with ethyl acetate (2×250 mL)
- washThe combined organics were washed with Kl 5% KHSO4 (1×50 mL)
- dry with materialaqueous Na2S2O3 (1×100 mL), then pH 7 phosphate buffer (1×100 mL), then brine (1×100 mL) and dried (Na2SO4)
- filtrationFiltration and evaporation of solvents
- waitleft carbobenzyloxy-L-prolinal (5.55 g) as an oil
Sources & evidence
- ORD record
- ord-87d4ccccda4c46d0aeedb79ba4b41e84
- Source dataset
- uspto-grants-1995_06
- Patent number
- US05424444
Linked notes
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