Description
Tetrahydro-4H-pyran-4-one is used in organic synthesis as building block for more complex chemical structures because it participate in a variety of cycloaddition reactions. Tetrahydro-4H-pyran-4-one is employed in the preparation of 4-methoxytetrahydropyran-4-yl protecting group, synthesis of symmetric tetra substituted methanes.
The methyl enol ether is a useful protecting agent for alcohols, e.g. in nucleotide synthesis, with the advantage over 3,4-Dihydro-2H-pyran. Tetrahydro-4H-pyran-4-one is also employed in a study of the enantioselective alpha-aminoxylation of ketones with nitrosobenzene and L-proline in an ionic liquid. It undergoes condensation reactions in the preparation of dipeptides and spiroimidazolones. Tetrahydro-4H-pyran-4-one is also employed in wittig reactions for the synthesis of Penicillins and in a ring of vitamin D3.
Application
Tetrahydro-4-pyrone is used in organic synthesis as a building block for more complex chemical structures because it participates in a variety of cycloaddition reactions. Tetrahydro-4H-pyran-4-one is employed in a study of the enantioselective alpha-aminoxylation of ketones with nitrosobenzene and L-proline in an ionic liquid and it undergoes condensation reactions in the preparation of dipeptides and spiroimidazolones. Tetrahydro-4H-pyran-4-one is also employed in wittig reactions for the synthesis of penicillins and in a ring of vitamin D3. Additionally, tetrahydro-4-pyrone is used as solvents in some reactions.
Chemical Properties
colorless to light yellow liquid
Uses
Tetrahydro-4-pyrone is used in organic synthesis as building block for more complex chemical structures because it participate in a variety of cycloaddition reactions.
Synthesis
The general procedure for the synthesis of tetrahydropyranone using pyran-4-one as starting material was as follows: 30 g of intermediate 2 was dissolved in a solvent mixture of 200 mL of toluene and 100 mL of methanol. Subsequently, 3g of 5% Pd/C catalyst was added and the hydrogenation reaction was carried out at room temperature for 5 hours. Upon completion of the reaction, the catalyst was removed by diafiltration and the filtrate was concentrated to dryness. Finally, 26 g of tetrahydropyranone was obtained by distillation purification in 86% yield.
Purification Methods
Purify the pyrone by repeated distillation, preferably in a vacuum. [Baker J Chem Soc 296 1944, IR: Olsen & Bredoch Chem Ber 91 1589 1958.] The oxime has m 87-88o and b 110-111o/13mm [Cornubert et al. Bull Soc Chim Fr 36 1950]. The 4-nitrophenylhydrazone forms orange-brown needles from EtOH, m 186o [Cawley & Plant J Chem Soc 1214 1938]. [Beilstein 17 I 131, 17 II 287, 17 III/IV 4171, 17/9 V 21.]
References
[1] Patent: CN108586405, 2018, A. Location in patent: Paragraph 0017; 0022
[2] Patent: EP1700853, 2006, A1. Location in patent: Page/Page column 13
[3] Patent: EP1700853, 2006, A1. Location in patent: Page/Page column 14
[4] Chemische Berichte, 1915, vol. 48, p. 684
