Benzyl Bromide → 5(S)-[1(S)-(Boc-Amino)-2-(p-methoxyphenyl)ethyl]-3(R)-(phenylmethyl)dihydrofuran-2-(3H)-one
Reaction equation
[C:1]([NH:8][C@H:9]([C@H:19]1[O:23][C:22](=[O:24])[CH2:21][CH2:20]1)[CH2:10][C:11]1[CH:16]=[CH:15][C:14]([O:17][CH3:18])=[CH:13][CH:12]=1)([O:3][C:4]([CH3:7])([CH3:6])[CH3:5])=[O:2].C[Si]([N-][Si](C)(C)C)(C)C.[Li+].[CH2:35](Br)[C:36]1[CH:41]=[CH:40][CH:39]=[CH:38][CH:37]=1>C1COCC1.CN1C(=O)N(C)CCC1>[C:1]([NH:8][C@H:9]([C@H:19]1[O:23][C:22](=[O:24])[C@H:21]([CH2:35][C:36]2[CH:41]=[CH:40][CH:39]=[CH:38][CH:37]=2)[CH2:20]1)[CH2:10][C:11]1[CH:16]=[CH:15][C:14]([O:17][CH3:18])=[CH:13][CH:12]=1)([O:3][C:4]([CH3:6])([CH3:7])[CH3:5])=[O:2]Participants
6
Reactant 3
Product 1
Reagents, catalysts & solvents 2
Procedure
In analogy with Example 5d), 4.17 g (12.44 mmol) of 5(S)-[1(S)-(Boc-amino)-2-(p-methoxyphenyl)ethyl]dihydrofuran-2-(3H)-one, dissolved in 22.4 ml of THF and 2.5 ml of DMPU, are deprotonated, at -70° C., with 24 ml of a 1M solution of lithium bis(trimethylsilyl)amide in THF, and alkylated (-75° C., 1 h) with 1.5 ml (12.44 mmol) of benzyl bromide. Protonation, at -75° C., with 4.6 ml of propionic acid and 4.6 ml of water, extraction and column chromatography (SiO2, methylene chloride/ether 25:1) yields the title compound: TLC Rf (C)=0,74; tRet (II)=16.6 min; FAB-MS (M+H)+ =426.
Workup
- customalkylated (-75° C., 1 h)
- extractionProtonation, at -75° C., with 4.6 ml of propionic acid and 4.6 ml of water, extraction and column chromatography (SiO2, methylene chloride/ether 25:1)
Sources & evidence
- ORD record
- ord-a0b4cfc14b8f4190a3333bb3a5cf3888
- Source dataset
- uspto-grants-1997_09
- Patent number
- US05663200
Reaction notes
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