Formaldehyde → 5-(Tetrahydro-pyran-2-yloxy)-pent-2-yn-1-ol

Temperature

-23 °C

To a solution of 8.0 mL (51 mmol) of 2-(3-butynyloxy)tetrahydro-2H-pyran in 150 mL of THF under nitrogen atmosphere at −23° C. was added dropwise a solution of 33 mL (53 mmol) of 1.6M butyllithium in hexanes, maintaining the temperature at −23° C. The resulting solution was stirred at 0° C. for 2 h, recooled to −23° C. and 2.4 g (76.5 mmol) of paraformaldehyde was added in several portions. The mixture was stirred at −23° C. for 1 h and let warm to room temperature and stirred for 18 h. The reaction mixture was poured into a large excess of ice water and extracted with ether. The organics were washed with brine until neutral, dried over MgSO4, filtered and concentrated in vacuo. The residue was kugelrohr distilled to provide 7.26 g (77%) of 5-(tetrahydro-2H-pyran-2-yloxy)-2-pentyn-1-ol as a colorless liquid. EI Mass Spec: 185.1 (M+H)+.

1. customrecooled to −23° C.
2. stirringThe mixture was stirred at −23° C. for 1 h
3. temperaturelet warm to room temperature
4. stirringstirred for 18 h
5. extractionextracted with ether
6. washThe organics were washed with brine until neutral,
7. dry with materialdried over MgSO4
8. filtrationfiltered
9. concentrationconcentrated in vacuo
10. distillationThe residue was kugelrohr distilled

ORD record

ord-9a642eb63aa14e0698a5ca5a4f5a8fe0

Source dataset

uspto-grants-2004_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06716833B2