Magnesium → t-butyl [(1S,2S,4S)-1-benzyl-2-hydroxy-4-isopropyl-5-hexenyl]carbamate

HRID 1655750Notes

Reaction equation

HRID 1655750 reaction equation
[C:1]([O:5][C:6]([NH:8][C@@H:9]([CH2:19][CH:20]1[CH2:25][CH2:24][CH2:23][CH2:22][CH2:21]1)[C@H:10]([CH2:12][C@@H:13]([CH:16]([CH3:18])[CH3:17])[CH:14]=[CH2:15])[OH:11])=[O:7])([CH3:4])([CH3:3])[CH3:2].C(C(C=C)CBr)(C)C.[Mg]>>[CH2:19]([C@H:9]([NH:8][C:6](=[O:7])[O:5][C:1]([CH3:2])([CH3:4])[CH3:3])[C@@H:10]([OH:11])[CH2:12][C@@H:13]([CH:16]([CH3:17])[CH3:18])[CH:14]=[CH2:15])[C:20]1[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=1

Participants

4

Reactant 3

HCID 5462224MagnesiumHCID 10631133(RS)-2-isopropyl-3-butenyl bromideHCID 67876495(alphaS,betaS)-beta-t-butoxycarbonylamino-alpha-[(S)-2-isopropyl-3-butenyl]cyclohexanepropanol

Product 1

HCID 57042285t-butyl [(1S,2S,4S)-1-benzyl-2-hydroxy-4-isopropyl-5-hexenyl]carbamateYield 49%

Procedure

In a manner analogous to that described in Example 1 for the preparation of (αS,βS)-β-t-butoxycarbonylamino-α-[(S)-2-isopropyl-3-butenyl]cyclohexanepropanol, from 56.6 g (320 mmol) of (RS)-2-isopropyl-3-butenyl bromide 7.7 g of magnesium and 24.2 g of N-t-butoxycarbonyl-L-phenylalanal26 there were obtained 15.6 g (49%) of t-butyl [(1S,2S,4S)-1-benzyl-2-hydroxy-4-isopropyl-5-hexenyl]carbamate as an epimer mixture. The desired (1S,2S,4S)-epimer was isolated as the less polar isomer. MS: 256 (M-benzyl)+, by flash chromatography on silica 5 gel using a 9:1 mixture of methylene chloride and ether as the eluting agent.

Sources & evidence

ORD record
ord-c6e3ecb8ef8c4c02b293e2118a55ef51
Source dataset
uspto-grants-1993_10
Patent number
US05250517

Reaction notes

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