Dichloromethane → ethyl 2-hydroxy-2-methylpent-4-enoate

Ethyl 2-oxopropanoate (1 g, 8.61 mmol) was taken in to DCM (5M) and cooled to −78 C. To this titanium tetrachloride (8.61 mL, 8.61 mmol) in dichloromethane (5 mL) was added and stirred the reaction mixture for 30 min at this temperature. To this reaction mixture allyltrimethylsilane (1.279 g, 11.20 mmol) was added drop wise at −78° C. and stirring was continued for 2 h. Then it was brought to 0° C. and quenched with saturated aq. sodium bicarbonate solution and stirred for 15 min, and filtered through celite bed and filtrate was evaporated under reduced pressure to afford colorless oil. The residue was purified by flash chromatography (silica, 230-400, 10% EtoAc/Pet ether) to obtain ethyl 2-hydroxy-2-methylpent-4-enoate B-37a (0.8 g, 5.06 mmol, 58.7% yield) as yellow liquid. 1H NMR (CDCl3, δ=7.26 ppm, 400 MHz): δ 5.84-5.72 (m, 1H), 5.15-5.09 (m, 2H), 4.29-4.19 (m, 2H), 2.56-2.37 (m, 2H), 1.43 (s, 3H), 1.31 (t, J=9.6 Hz, 3H).

1. temperaturecooled to −78 C
2. stirringstirring
3. waitwas continued for 2 h
4. customwas brought to 0° C.
5. customquenched with saturated aq. sodium bicarbonate solution
6. stirringstirred for 15 min
7. filtrationfiltered through celite bed and filtrate
8. customwas evaporated under reduced pressure
9. customto afford colorless oil
10. customThe residue was purified by flash chromatography (silica, 230-400, 10% EtoAc/Pet ether)

ORD record

ord-93eacaec2d724974a9c3e36db47660bb

Source dataset

uspto-grants-2016_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09326973B2