Reaction #336848

Reaction equation

(±)-3,4-dihydro-2H-pyran-2-methanol

acetic anhydride

pyridine

→

(±)-3,4-dihydro-2H-pyran-2-yl-methyl acetate

Yield 86.0%

Solvents

—

hexanes

ethyl acetate

Conditions

Workup

1. 1
   Otherthe resultant reaction mixture
2. 2
   Temperatureto warm to room temperature
3. 3
   OtherThe resultant reaction mixture
4. 4
   workup.STIRRINGto stir for an additional 8 hours
5. 5
   Otherafter reaching room temperature
6. 6
   ConcentrationThe reaction mixture was concentrated in vacuo at 35° C.
7. 7
   workup.ADDITIONthe resultant residue was diluted
8. 8
   OtherThe resultant mixture was transferred to a separatory funnel
9. 9
   Washsequentially washed with deionized water (3×1 L), saturated aqueous NaHCO3 (2×10 L), and brine (1.0 L)
10. 10
    DryingThe organic layer was dried over sodium sulfate
11. 11
    Concentrationconcentrated in vacuo at 35° C.

Procedure

A mixture of (±)-3,4-dihydro-2H-pyran-2-methanol (514 g, 4.51 mol, 1 eq) and acetic anhydride (621 g, 6.09 mol, 1.35 eq) was cooled to 0° C. To the resultant mixture was added pyridine (35.6 g, 0.45 mol, 0.1 eq) and the resultant reaction mixture was allowed to warm to room temperature with stirring. The resultant reaction mixture was allowed to stir for an additional 8 hours after reaching room temperature and was shown to be complete by thin-layer chromatography (2:1 hexanes:ethyl acetate, 12 staining). The reaction mixture was concentrated in vacuo at 35° C. and the resultant residue was diluted using ethyl acetate (2 L). The resultant mixture was transferred to a separatory funnel and sequentially washed with deionized water (3×1 L), saturated aqueous NaHCO3 (2×10 L), and brine (1.0 L). The organic layer was dried over sodium sulfate and concentrated in vacuo at 35° C. to provide (±)-3,4-dihydro-2H-pyran-2-yl-methyl acetate as a clear liquid (605.9 g, 86% yield). 1H NMR (300 MHz, CDCl3) δ 1.6-2.2 (m, 4 H), 2.1 (s, 3 H), 4.2 (m, 3 H), 4.8 (m, 1 H), 6.4 (m, 1 H).

Source