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

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

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.

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