Lithium Hexamethyldisilazide → 3(R)-But-2-enyl-5(S)-[5-tert-butyl-diphenylsilyloxy-1(S)-tert-butoxycarbonylamino-3,3-dimethyl-pentyl]-2-oxo-tetrahydrofuran

HRID 863332Notes

Reaction equation

HRID 863332 reaction equation
C[Si]([N-][Si](C)(C)C)(C)C.[Li+].[Si:11]([O:28][CH2:29][CH2:30][C:31]([CH3:49])([CH3:48])[CH2:32][C@@H:33]([C@H:42]1[O:46][C:45](=[O:47])[CH2:44][CH2:43]1)[NH:34][C:35]([O:37][C:38]([CH3:41])([CH3:40])[CH3:39])=[O:36])([C:24]([CH3:27])([CH3:26])[CH3:25])([C:18]1[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=1)[C:12]1[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1>O1CCCC1.C(Br)C=CC>[CH2:17]([C@@H:44]1[CH2:43][C@@H:42]([C@@H:33]([NH:34][C:35]([O:37][C:38]([CH3:39])([CH3:40])[CH3:41])=[O:36])[CH2:32][C:31]([CH3:49])([CH3:48])[CH2:30][CH2:29][O:28][Si:11]([C:24]([CH3:26])([CH3:27])[CH3:25])([C:18]2[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=2)[C:12]2[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=2)[O:46][C:45]1=[O:47])[CH:12]=[CH:13][CH3:14]

Participants

5

Reactant 2

HCID 2733832Lithium HexamethyldisilazideHCID 1317205385(S)-[5-tert-butyl-diphenylsilyloxy-1(S)-tert-butoxycarbonylamino-3,3-dimethyl-pentyl]-2-oxo-tetrahydrofuran

Product 1

HCID 676259163(R)-But-2-enyl-5(S)-[5-tert-butyl-diphenylsilyloxy-1(S)-tert-butoxycarbonylamino-3,3-dimethyl-pentyl]-2-oxo-tetrahydrofuran

Reagents, catalysts & solvents 2

HCID 8028TetrahydrofuranSolventHCID 1224142-Butene, 1-bromo-Solvent

Procedure

4.6 ml of a 1M lithium bis-(trimethylsilyl)amide solution in tetrahydrofuran and 0.26 ml of crotyl bromide (89%, 5.7:1 E:Z) are added to 1.22 g of 5(S)-[5-tert-butyl-diphenylsilyloxy-1(S)-tert-butoxycarbonylamino-3,3-dimethyl-pentyl]-2-oxo-tetrahydrofuran analogously to Example 74d). Working up after 5 h and subsequent purification by means of FC over silica gel (mobile phase C) gives the title compound, of uniform (R) configuration on C-3, as a 2E/2Z isomer mixture which cannot be separated: (Rf (C)=0.62; FAB-MS: (M+H)+ =608).

Workup

  1. customsubsequent purification by means of FC over silica gel (mobile phase C)

Sources & evidence

ORD record
ord-88a68c4c9e9d49b2896d29770a34430f
Source dataset
uspto-grants-1998_02
Patent number
US05719141

Reaction notes

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