Acetic Acid → 5(S)-[5-Benzyloxy-1(S)-tert-butoxycarbonylamino-3,3-dimethyl-pentyl]-2-oxotetrahydrofuran

HRID 863272Notes

Reaction equation

HRID 863272 reaction equation
[CH2:1]([O:8][CH2:9][CH2:10][C:11]([CH3:32])([CH3:31])[CH2:12][C@H:13]([NH:23][C:24]([O:26][C:27]([CH3:30])([CH3:29])[CH3:28])=[O:25])[CH:14](O)[CH2:15][CH2:16][C:17]([O:19]CC)=[O:18])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.C(O)(=O)C>C1(C)C=CC=CC=1.C(OCC)(=O)C>[CH2:1]([O:8][CH2:9][CH2:10][C:11]([CH3:31])([CH3:32])[CH2:12][C@@H:13]([C@H:14]1[O:18][C:17](=[O:19])[CH2:16][CH2:15]1)[NH:23][C:24]([O:26][C:27]([CH3:29])([CH3:30])[CH3:28])=[O:25])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1

Participants

5

Reactant 2

HCID 176Acetic AcidHCID 131720519ethyl 9-benzyloxy-5(S)-tert-butoxycarbonylamino-4(R,S)-hydroxy-7,7-dimethyl-nonanoate

Product 1

HCID 867521045(S)-[5-Benzyloxy-1(S)-tert-butoxycarbonylamino-3,3-dimethyl-pentyl]-2-oxotetrahydrofuran

Reagents, catalysts & solvents 2

HCID 1140TolueneSolventHCID 8857Ethyl AcetateSolvent

Procedure

5.52 g of the ethyl 9-benzyloxy-5(S)-tert-butoxycarbonylamino-4(R,S)-hydroxy-7,7-dimethyl-nonanoate obtained as the crude product are refluxed in 100 ml of toluene and 4 ml of glacial acetic acid at 110° C. under argon for 4.5 h. After the reaction mixture has cooled, it is diluted with ethyl acetate and worked up in the customary manner. The crude product is purified by chromatography over silica gel (mobile phase B), the two 5(S) and 5(R) stereoisomers being separated. This gives the pure title compound (diastereomer I) as a yellowish oil: Rf (B)=0.26; FAB-MS: (M+H)+ =406; and diastereomer II: Rf (B)=0.22.

Workup

  1. temperatureAfter the reaction mixture has cooled
  2. customThe crude product is purified by chromatography over silica gel (mobile phase B)
  3. customthe two 5(S) and 5(R) stereoisomers being separated

Sources & evidence

ORD record
ord-e607fe090dcf423d85012f17ab8204c7
Source dataset
uspto-grants-1998_02
Patent number
US05719141

Reaction notes

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