Methyl 2-propen-1-yl carbonate → isopropyl 5-allyloxy-2(S)-(tert-butoxycarbonylamino)pentanoate

HRID 17817

Reaction equation

HRID 17817 reaction equation
[C:1]([O:5][C:6]([NH:8][C@@H:9]([CH2:16][CH2:17][CH2:18][OH:19])[C:10]([O:12][CH:13]([CH3:15])[CH3:14])=[O:11])=[O:7])([CH3:4])([CH3:3])[CH3:2].C(=O)(OC)O[CH2:22][CH:23]=[CH2:24].C1C=CC(P(C2C(C3C(P(C4C=CC=CC=4)C4C=CC=CC=4)=CC=C4C=3C=CC=C4)=C3C(C=CC=C3)=CC=2)C2C=CC=CC=2)=CC=1.CCOCC.CCCCCC>C1COCC1.CCOCC.C1C=CC(/C=C/C(/C=C/C2C=CC=CC=2)=O)=CC=1.C1C=CC(/C=C/C(/C=C/C2C=CC=CC=2)=O)=CC=1.C1C=CC(/C=C/C(/C=C/C2C=CC=CC=2)=O)=CC=1.[Pd].[Pd]>[CH2:24]([O:19][CH2:18][CH2:17][CH2:16][C@H:9]([NH:8][C:6]([O:5][C:1]([CH3:2])([CH3:3])[CH3:4])=[O:7])[C:10]([O:12][CH:13]([CH3:15])[CH3:14])=[O:11])[CH:23]=[CH2:22]

Participants

8

Reactant 4

HCID 534788Methyl 2-propen-1-yl carbonateHCID 634876Binap, (A+-)-HCID 21080142isopropyl 2(S)-(tert-butoxycarbonylamino)-5-hydroxypentanoateHCID 21584099Diethylether hexane

Product 1

HCID 21080143isopropyl 5-allyloxy-2(S)-(tert-butoxycarbonylamino)pentanoate

Reagents, catalysts & solvents 3

HCID 9811564Bis(dibenzylideneacetone)palladiumCatalystHCID 3283Diethyl EtherSolventHCID 8028TetrahydrofuranSolvent

Procedure

A degassed mixture of isopropyl 2(S)-(tert-butoxycarbonylamino)-5-hydroxypentanoate (product of step 26C, 17.6 g, 63.9 mmol), allyl methyl carbonate (24.0 ml, 213 mmol), Pd2(dba)3 (1.62 g, 1.78 mmol) and BINAP (4.42 g, 7.10 mmol) in THF (150 mL) was refluxed under nitrogen for 3 hours. After cooling to room temperature, the reaction was diluted with ether, filtered through celite and evaporated giving a dark brown syrup. Flash chromatography of the residue (silica gel, 30% ether/hexane) gave isopropyl 5-allyloxy-2(S)-(tert-butoxycarbonylamino)pentanoate as a viscous colorless oil, 16.3 g (81%): 1H NMR (300 MHz, Chloroform-D) δ 5.88 (ddt, 1H, 17.4, 10.4, 5.5), 5.28 (m, 1H), 5.22-5.11 (m, 1H), 5.02 (sept., 1H, J=6.2 Hz), 4.21 (br t, 1H, J=6.7 Hz), 3.94 (dt, 2 H, J=5.9, 1.5 Hz), 3.42 (t, 2H, J=5.9 Hz), 1.90-1.82 (m, 1H), 1.75-1.57 (m, 3H), 1.42 (s, 9H), 1.21 (d, 3H, J=6.2 Hz), 1.19 (d, 3H, J=6.2 Hz). LCMS m/z 316 (M+H)+.

Workup

  1. temperaturewas refluxed under nitrogen for 3 hours
  2. filtrationfiltered through celite
  3. customevaporated
  4. customgiving a dark brown syrup

Sources & evidence

ORD record
ord-d17b8ec878fd46fc8abb92f0f4d5a39f
Source dataset
uspto-grants-2010_06
Patent number
US07741281B2

Linked notes

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