Pivaloyl chloride → 2,2-Dimethyl-propionic acid (E)-(2S,3S,4S,5S)-3,5-dimethoxy-2,4-dimethyl-oct-6-enyl ester

HRID 1427751Notes

Reaction equation

HRID 1427751 reaction equation
[CH3:1][O:2][C@H:3]([C@@H:8]([CH3:15])[C@@H:9]([O:13][CH3:14])/[CH:10]=[CH:11]/[CH3:12])[C@@H:4]([CH3:7])[CH2:5][OH:6].[C:16](Cl)(=[O:21])[C:17]([CH3:20])([CH3:19])[CH3:18]>N1C=CC=CC=1>[CH3:1][O:2][C@H:3]([C@@H:8]([CH3:15])[C@@H:9]([O:13][CH3:14])/[CH:10]=[CH:11]/[CH3:12])[C@@H:4]([CH3:7])[CH2:5][O:6][C:16](=[O:21])[C:17]([CH3:20])([CH3:19])[CH3:18]

Participants

4

Reactant 2

HCID 62493Pivaloyl chlorideHCID 86675849(E)-(2S,3S,4S,5S)-3,5-Dimethoxy-2,4-dimethyl-oct-6-en-1-ol

Product 1

HCID 866758502,2-Dimethyl-propionic acid (E)-(2S,3S,4S,5S)-3,5-dimethoxy-2,4-dimethyl-oct-6-enyl ester

Reagents, catalysts & solvents 1

HCID 1049PyridineSolvent

Procedure

To (E)-(2S,3S,4S,5S)-3,5-Dimethoxy-2,4-dimethyl-oct-6-en-1-ol (1.5 g, 6.94 mmol) in anhydrous pyridine (20 ml) at 0° C. and under an atmosphere of nitrogen was added pivaloyl chloride (1.33 ml, 10.7 mmol). The reaction was warmed to room temperature and stirred for 2 hours, after which it was quenched with saturated ammonium chloride and extracted with dichloromethane (2×). The combined organic layers were dried by passing through a hydrophobic frit and concentrated in vacuo. The product was purified by flash chromatography (SiO2, iHex/EtOAc, 20:1 then 1:1) to afford 2.0 g (100%) as a clear oil. 1H NMR (300 MHz, CDCl3) δ 5.67 (dq, J=15.3 Hz, 6.6 Hz, 1H), 5.21 (m, 1H), 4.23 (dd, J=10.6 Hz, 3.3 Hz, 1H), 4.1 (dd, J=10.6 Hz, 6.0 Hz, 1H), 3.52 (dd, J=10.0 Hz, 2.0 Hz, 1H), 3.42 (s, 3H), 3.34 (t, J=9.3 Hz, 1H), 3.25 (s, 3H), 1.96 (m, 1H), 1.78 (dd, J=6.4 Hz, 1.5 Hz, 3H), 1.68 (m, 1H), 1.24 (s, 9H), 0.90 (d, J=7.1 Hz, 3H), 0.76 (d, J=7.1 Hz, 3H).

Workup

  1. customafter which it was quenched with saturated ammonium chloride
  2. extractionextracted with dichloromethane (2×)
  3. customThe combined organic layers were dried
  4. concentrationconcentrated in vacuo
  5. customThe product was purified by flash chromatography (SiO2
  6. customiHex/EtOAc, 20:1 then 1:1) to afford 2.0 g (100%) as a clear oil

Sources & evidence

ORD record
ord-38fe9bea08b64f9f89bb1c8dbb6f1415
Source dataset
uspto-grants-2015_01
Patent number
US08933015B2

Reaction notes

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