Pharmacognosy - medicinal plants (herbs)
Pharmacognosy - medicinal plants (herbs)

Theme XVIII: Heterocycles

Hexagonal heterocyclic compounds: The Pyran and Pyrimidine

Characteristics of hexagonal heterocyclic compounds. The Pyran and Pyrimidine. Pyranose structures. Glucose.

Hexagonal heterocyclic compounds

The hexagonal heterocyclic compounds can be presented with 1 or 2 heteroatoms among which are the pyrimidine and pyran.

Pyran

Pyrimidine



Study of Pyran

This compound is a cyclic unsubstituted hexagonal structure, without charge and with two double bonds, the heteroatom is oxygen and in its position representation should be indicated the two hydrogen atoms to differentiate the two isomers.



α - Pyran

γ - Pyran



These structures do not present aromatic characteristics and in the system are just 4 π electrons. The pyran derivatives are possible to obtain only through organic synthesis however appear naturally in numerous compounds.


In the Pyran reduction reaction is first obtained the dihydropyran and then the tetrahydropyran.

Dihydropyran

Tetrahydropyran



Various organic structures have in their carbon skeleton tetrahydropyran hexagonal rings such carbohydrates, which are glucose polymers. These structures are called pyranose. For example the structure of glucose.

D glucose

see also

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