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

Temperature

-78 °C

To this mixture 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. using dry ice/acetone bath for 45 min. Then, a mixture of 5 g of HMPA and 10.92 g of allyl iodide was added via canula. At the end of about 90% addition of this mixture, white precipitate formed suddenly. This mixture was stirred at −78° C. for 20 min, then the dry ice/acetone bath was removed and the stirring was continued to allow the reaction mixture to warm to r.t. over 30 min. At which time the precipitate dissolved, the reaction mixture was poured into ice-water (100 mL) and ether (50 mL). The two layers were separated, and 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 obtain 8.75 g (95% yield) of the title compound as a yellow liquid.

1. customfor 45 min
2. additionwas added via canula
3. additionAt the end of about 90% addition of this mixture, white precipitate
4. customformed suddenly
5. stirringThis mixture was stirred at −78° C. for 20 min
6. customthe dry ice/acetone bath was removed
7. temperatureto warm to r.t. over 30 min
8. dissolutionAt which time the precipitate dissolved
9. additionthe reaction mixture was poured into ice-water (100 mL) and ether (50 mL)
10. customThe two layers were separated
11. extractionthe aqueous layer was extracted with ether (3×50 mL)
12. washThe combined organic layers were washed with brine
13. dry with materialdried (K2CO3)
14. filtrationfiltered
15. concentrationconcentrated in vacuo

ORD record

ord-81c2bdeb75084386a10e7d1ff02d538c

Source dataset

uspto-grants-2014_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08735385B2