Reaktion #89112

Reaktionsgleichung

(Carbethoxymethylene)triphenylphosphorane

octahydroisobenzofuran-1-ol

→

(E)-ethyl 3-(2-(hydroxymethyl)cyclohexyl)acrylate

Lösungsmittel

acetonitrile

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigewas used for next step without further purification
2. 2
   SonstigeAcetonitrile was removed in vacuo
3. 3
   workup.ADDITIONthe resulting residue was diluted with ether which
4. 4
   FiltrationThe white precipitate was filtered off
5. 5
   Waschenwashed with cold ether
6. 6
   Einengenconcentrated in vacuo
7. 7
   Sonstigeto give crude product which
8. 8
   Sonstigewas purified by chromatograph

Vorschrift

DIBAL-H (1M in toluene) (35.2 mmol, 35.2 mL) was added dropwise to a solution of hexahydroisobenzofuran-1(3H)-one (33.5 mol, 4.7 g) in anhydrous ether (100 mL) at −10° C. under argon. The resulting mixture was stirred at −10° C. for 30 min under argon and quenched with MeOH (30 mL). The mixture was stirred at rt for overnight and the resulting suspension was added saturated Rochelle's salt aqueous solution and stirred for additional 30 min at rt. The organic layer was separated and washed with saturated Rochelle's salt aqueous solution. The combined aqueous layer was extracted with ether (3×). The organic layer were combined, dried with dried with MgSO4 and concentrated in vacuo to give lactol octahydroisobenzofuran-1-ol which was used for next step without further purification. (Carbethoxymethylene)triphenylphosphorane (17.7 g, 50.7 mmol) was added to a solution of the above described octahydroisobenzofuran-1-ol in acetonitrile (100 mL) and the resulting mixture was refluxed at 85° C. overnight. Acetonitrile was removed in vacuo and the resulting residue was diluted with ether which was stirred at rt for 2 h. The white precipitate was filtered off and washed with cold ether. All ether portion was combined and concentrated in vacuo to give crude product which was purified by chromatograph to afford desired (E)-ethyl 3-(2-(hydroxymethyl)cyclohexyl)acrylate as colorless oil (Y: 78.9% over two steps). 1H NMR (CDCl3, 400 MHz) δ 7.12-7.05 (m, 1H), 5.80 (d, 1H), 4.15-4.09 (m, 2H), 3.40-3.37 (m, 2H), 2.63-2.59 (m, 1H), 1.80-1.29 (m, 9H), 1.25-1.19 (m, 3H).

Quelle