DHP

(Dihydropyran)

Other Names:

3,4-Dihydro-2H-pyran

General Information:

Structure:

CAS Number: 110-87-2

Molecular Weight: 84.12 g/mol

Appearance: Colorless liquid

Melting Point: -70 C

Boiling Point: 86 C

Density: 0.922 g/mL

Dihydropyran (DHP) is an organic compound commonly used to install tetrahydropyranyl (THP) protecting groups on alcohols and amines.

Common Uses:

Reagent for the THP protection of alcohols

Procedure excerpt:

A mixture of the SM (4.1 g, 20 mmol), 3,4-dihydro-2H-pyran (2.0 g, 24 mmol), and p-TsOH monohydrate (100 mg, 0.52 mmol) in anhydrous DCM (70 mL) was stirred at RT . . .

[full procedure]

Reagent for the THP protection of amines

Procedure excerpt:

To a mixture of the SM (750 mg, 3.83 mmol) in THF (15 mL) was added 3,4-dihydro-2H-pyran (2.8 g, 7.66 mmol) and p-TsOH (132 mg, 0.77 mmol). The reaction mixture . . .

[full procedure]

References:

1) Patent Reference: WO2005082859, page 296, (25.9 MB)

2) Patent Reference: WO2016011390, page 217, (20.2 MB)

3) Pearson, A. J.; Roush, W. R.; Handbook of Reagents for Organic Synthesis; Activating Agents and Protecting Groups

4) Wikipedia: Dihydropyran (link)

5) www.sigmaaldrich.com: 3,4-Dihydro-2H-pyran (link)