Formaldehyde → Ethyl 4-methyl-2-methylenepentanoate

Bis(trimethylsilyl)amine (9.50 g, 59.0 mmol) in 250 ml of THF was metallated by 23.5 ml (59.0 mmol) of 2.5 M nBuLi in hexanes at −78° C. This mixture was additionally stirred for 0.5 h at room temperature, then cooled again to −78° C., and 10.0 g (53.7 mmol) of ethyl 2-acetyl-4-methylpentanoate was added. The resulting mixture was stirred for 1 h at room temperature, cooled to −78° C., and 8.0 g (09.27 mmol) of paraformaldehyde was added. This mixture was stirred overnight at room temperature, then filtered through glass frit (G3), and evaporated to dryness. Fractional rectification of the residue gave the title product, 50-55° C./4 mm Hg. Yield 6.50 g (78%).

1. temperaturecooled again to −78° C.
2. stirringThe resulting mixture was stirred for 1 h at room temperature
3. temperaturecooled to −78° C.
4. stirringThis mixture was stirred overnight at room temperature
5. filtrationfiltered through glass frit (G3)
6. customevaporated to dryness

ORD record

ord-2bfe30003a604f8d995ac7716586ee11

Source dataset

uspto-grants-2015_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08933256B2