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

Temperature

-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 cannula. 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 obtain 8.75 g (95% yield) of the title compound as a yellow liquid.

1. additionwas added via cannula
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 record

ord-9ff914d5888e4c46a8c7ee533e6fba58

Source dataset

uspto-grants-2014_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08796278B2