Allyl iodide → tetrahydro-4-(2-propen-1-yl)-2H-Pyran-4-carboxylic acid methyl ester

Temperatur

-78 °C

To this was added tetrahydro-pyran-4-carboxylic acid methyl ester (7.2 g, 50 mmol) in THF (10 mL). There was almost no color change (light a little bit). This was stirred at −78° C. for 45 min. Then, a mixture of 5 g of HMPA and 10.92 g of allyl iodide was added via canula. Towards 90% of addition, white precipitate formed suddenly. This mixture was stirred at −78° C. for 20 min, then, the dry ice bath was removed and the stirring was continued to allow the reaction mixture to warm to r.t. over 30 min. When the precipitate was dissolved, the reaction mixture was poured into ice-water (100 mL) and ether (50 mL). The two layers were separated; the aqueous layer was extracted with ether (3×50 mL). The combined organic layers were washed with brine, dried (K2CO3), filtered, and concentrated in vacuo to get 8.75 g (95% yield) of the title compound as a yellow liquid.

1. additionwas added via canula
2. additionTowards 90% of addition, white precipitate
3. customformed suddenly
4. stirringThis mixture was stirred at −78° C. for 20 min
5. customthe dry ice bath was removed
6. temperatureto warm to r.t. over 30 min
7. dissolutionWhen the precipitate was dissolved
8. additionthe reaction mixture was poured into ice-water (100 mL) and ether (50 mL)
9. customThe two layers were separated
10. extractionthe aqueous layer was extracted with ether (3×50 mL)
11. washThe combined organic layers were washed with brine
12. dry with materialdried (K2CO3)
13. filtrationfiltered
14. concentrationconcentrated in vacuo

ORD-Eintrag

ord-2da4b9f1bb1b4c91804ec2cd7cbfdbb7

Quelldatensatz

uspto-grants-2013_02

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08383814B2