Boron trifluoride etherate → HCID 86701848, compound

Temperature

-30 °C

Crotonaldehyde cis/trans (16 g, 230 mmol) was dissolved in methylene chloride and cooled to −30° C. With stirring, and under nitrogen, BF3.OEt2 (3.6 ml, 29 mmol) was added gradually. A solution of 5-methyl-3-methylenehex-1-ene 2 (21 g, 191 mmol) in methylene chloride (50 ml) was then added at −30° C. over 1 h and the pot allowed to warm to −20° C. The solution was stirred at this temperature for a further 1.5 h before being poured onto 2M NaOH (100 ml). After brief agitation the phases were separated and the lower organic phase washed with water (100 ml) and brine (2×100 ml). The combined aqueous phases were extracted with MTBE (150 ml), phase separated and the upper organic part washed to neutral with brine. The organic phases were combined, dried (Na2SO4) and concentrated in vacuo to afford 3b as a pale yellow oil (33 g, 94% yield; 98% pure). The product was used in the next steps without further purification.

1. temperatureto warm to −20° C
2. stirringThe solution was stirred at this temperature for a further 1.5 h
3. customAfter brief agitation the phases were separated
4. washthe lower organic phase washed with water (100 ml) and brine (2×100 ml)
5. extractionThe combined aqueous phases were extracted with MTBE (150 ml), phase
6. customseparated
7. washthe upper organic part washed to neutral with brine
8. dry with materialdried (Na2SO4)
9. concentrationconcentrated in vacuo

ORD record

ord-1c021ef6f04844c4a0a39cbfef8498b9

Source dataset

uspto-grants-2015_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08999914B2