Lithium Hexamethyldisilazide → 5(S)-[1(S)-(Boc-amino)-2-phenylethyl]-3(R)-[(p-benzyloxyphenyl)methyl]dihydrofuran-2-(3H)-one

HRID 1377161Notes

Reaction equation

HRID 1377161 reaction equation
[C:1]([NH:8][C@H:9]([C@H:17]1[O:21][C:20](=[O:22])[CH2:19][CH2:18]1)[CH2:10][C:11]1[CH:16]=[CH:15][CH:14]=[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+].[CH2:33]([O:40][C:41]1[CH:48]=[CH:47][C:44]([CH2:45]I)=[CH:43][CH:42]=1)[C:34]1[CH:39]=[CH:38][CH:37]=[CH:36][CH:35]=1.CCCCCC.C(OCC)(=O)C>C1COCC1.CN1CCCN(C)C1=O>[C:1]([NH:8][C@H:9]([C@H:17]1[O:21][C:20](=[O:22])[C@H:19]([CH2:45][C:44]2[CH:47]=[CH:48][C:41]([O:40][CH2:33][C:34]3[CH:39]=[CH:38][CH:37]=[CH:36][CH:35]=3)=[CH:42][CH:43]=2)[CH2:18]1)[CH2:10][C:11]1[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=1)([O:3][C:4]([CH3:6])([CH3:7])[CH3:5])=[O:2]

Participants

7

Reactant 4

HCID 2733832Lithium HexamethyldisilazideHCID 10870461tert-butyl(1S)-1-[(2S)-5-oxotetrahydrofuran-2-yl]-2-phenylethylcarbamateHCID 11723738p-Benzyloxybenzyl iodideHCID 21226206Ethyl acetate hexane

Product 1

HCID 156595565(S)-[1(S)-(Boc-amino)-2-phenylethyl]-3(R)-[(p-benzyloxyphenyl)methyl]dihydrofuran-2-(3H)-one

Reagents, catalysts & solvents 2

HCID 8028TetrahydrofuranSolvent3×HCID 816462(1H)-Pyrimidinone, tetrahydro-1,3-dimethyl-Solvent

Procedure

In analogy with Example 1h), 1.13 g (3.70 mmol) of 5(S)-[1(S)-(Boc-amino)-2-phenylethyl]dihydrofuran-2-(3H)-one [Example 2b)], dissolved in 4.8 ml of THF and 0.75 ml of 1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone, are deprotonated, at -75° C., with 7.25 ml of a 1M solution of lithium bis(trimethylsilyl)amide in THF, and alkylated (15 min) with 1.2 g (3.7 mmol) of p-benzyloxybenzyl iodide (Example 1d)) in 2 ml of THF. Column chromatography (SiO2, hexane/ethyl acetate, 2:1) affords the pure title compound: TLC Rf (D)=0.30; tRet (I)=28.2 min; FAB-MS (M+H)+ =502.

Workup

  1. customalkylated (15 min)

Sources & evidence

ORD record
ord-841dc93bb8354bf48f201028471ecbd2
Source dataset
uspto-grants-1997_09
Patent number
US05663200

Reaction notes

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