Acetic Anhydride → Ethyl 2-(acetoxymethyl)-2-(tert-butoxycarbonylamino)hex-5-enoate

HRID 579513Notes

Reaction equation

HRID 579513 reaction equation
[C:1]([O:5][C:6]([NH:8][C:9]([CH2:19][OH:20])([CH2:15][CH2:16][CH:17]=[CH2:18])[C:10]([O:12][CH2:13][CH3:14])=[O:11])=[O:7])([CH3:4])([CH3:3])[CH3:2].CN(C1C=CC=CN=1)C.[C:30](OC(=O)C)(=[O:32])[CH3:31]>ClCCl>[C:30]([O:20][CH2:19][C:9]([NH:8][C:6]([O:5][C:1]([CH3:3])([CH3:2])[CH3:4])=[O:7])([CH2:15][CH2:16][CH:17]=[CH2:18])[C:10]([O:12][CH2:13][CH3:14])=[O:11])(=[O:32])[CH3:31]

Participants

5

Reactant 3

HCID 7918Acetic AnhydrideHCID 218852-DimethylaminopyridineHCID 71579992Ethyl 2-(tert-butoxycarbonylamino)-2-(hydroxymethyl)hex-5-enoate

Product 1

HCID 86663718Ethyl 2-(acetoxymethyl)-2-(tert-butoxycarbonylamino)hex-5-enoateYield 80%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

A solution of the ethyl 2-(tert-butoxycarbonylamino)-2-(hydroxymethyl)hex-5-enoate (10.0 g, 35 mmol) and dimethylaminopyridine (4.48 g, 35 mmol) in dichloromethane (100 mL) was treated with acetic anhydride and stirred at room temperature overnight. The solution was concentrated and the resulting residue purified using a combiflash system (89 g column, eluting with 20-50% ethyl acetate in heptanes) to give ethyl 2-(acetoxymethyl)-2-(tert-butoxycarbonylamino)hex-5-enoate (10 g, 80%). 1H NMR (CDCl3) δ 5.78-5.68 (m, 1H), 5.55 (bs, 1H), 5.03-4.93 (m, 2H), 4.73 (d, J=11.0 Hz, 1H) 4.32 (d, J=11.0 Hz, 1H,), 4.20 (q, J=7.2 Hz, 2H), 2.36 (m, 1H), 2.07-2.05 (m, 1H), 2.02 (s, 3H), 1.89-1.75 (m, 2H), 1.43 (m, 9H), 1.27 (t, J=7.2 Hz, 3H). MS found for C16H27NO6 m/z[330(M+1)].

Workup

  1. concentrationThe solution was concentrated
  2. customthe resulting residue purified
  3. washa combiflash system (89 g column, eluting with 20-50% ethyl acetate in heptanes)

Sources & evidence

ORD record
ord-c7b5c4fee8504f0bb54ff0519a0cda7f
Source dataset
uspto-grants-2015_05
Patent number
US09040703B2

Reaction notes

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