Acetic acid, 2-(triphenylphosphoranylidene)-, ethyl ester → (E)-Ethyl 3-cyclobutylacrylate

Ethyl 2-triphenylphosphoranylideneacetate (9.32 g, 26.74 mmol) was added to a solution of cyclobutanecarbaldehyde, 45a, (1.50 g, 17.83 mmol) in dichloromethane (30 mL). The reaction mixture was briefly purged with nitrogen and capped allowed to stir at room temperature overnight. All volatiles were removed at reduced pressure and the residue was dissolved in Et2O (100 mL) and hexanes (25 mL). The resulting pink precipitate was filtered off and discarded. The solvent was removed from the filtrate at reduced pressure. The crude product was purified via silica gel chromatography (0-20% EtOAc/Hexanes gradient) to afford 646 mg (23%) of the desired product: 1H NMR (400 MHz, CDCl3) δ 7.05 (dd, J=15.6, 6.8 Hz, 1H), 5.73 (dd, J=15.6, 1.4 Hz, 1H), 4.29-4.09 (m, 2H), 3.20-2.98 (m, 1H), 2.28-2.09 (m, 2H), 2.04-1.78 (m, 4H), 1.36-1.18 (m, 3H).

1. customThe reaction mixture was briefly purged with nitrogen
2. customcapped
3. customAll volatiles were removed at reduced pressure
4. dissolutionthe residue was dissolved in Et2O (100 mL)
5. filtrationThe resulting pink precipitate was filtered off
6. customThe solvent was removed from the filtrate at reduced pressure
7. customThe crude product was purified via silica gel chromatography (0-20% EtOAc/Hexanes gradient)

ORD-Eintrag

ord-88703d03be0b4b878bf013838905421c

Quelldatensatz

uspto-grants-2015_06

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US09051319B2