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Pyrrolidine, also known as tetrahydropyrrole, is an organic compound with the molecular formula (CH 2) 4 NH. It is a cyclic secondary amine , also classified as a saturated heterocycle . It is a colourless liquid that is miscible with water and most organic solvents.
Pyrrole is an extremely weak base for an amine, with a conjugate acid pK a of −3.8. The most thermodynamically stable pyrrolium cation (C 4 H 6 N +) is formed by protonation at the 2 position. Substitution of pyrrole with alkyl substituents provides a more basic molecule—for example, tetramethylpyrrole has a conjugate acid pK a of +3.7.
Nicotine is a molecule containing a pyrrolidine ring attached to a ring of pyridine (other heterocyclic amine). Nicotine belongs to a group of compounds known as alkaloids, which are naturally occurring organic compounds with nitrogen in them. Pyrrole is another compound made up of molecules with a five-membered heterocyclic ring. These ...
Included are pyridine, thiophene, pyrrole, and furan. Another large class of organic heterocycles refers to those fused to benzene rings. For example, the fused benzene derivatives of pyridine, thiophene, pyrrole, and furan are quinoline, benzothiophene, indole, and benzofuran, respectively. The fusion of two benzene rings gives rise to a third ...
Skeletal formula of retronecine, a pyrrolizidine alkaloid found in the common groundsel (Senecio vulgaris) and comfrey (Symphytum spp.) . Pyrrolizidine alkaloids (PAs), sometimes referred to as necine bases, are a group of naturally occurring alkaloids based on the structure of pyrrolizidine.
Pyrrolines, also known under the name dihydropyrroles, are three different heterocyclic organic chemical compounds that differ in the position of the double bond.Pyrrolines are formally derived from the aromate pyrrole by hydrogenation. 1-Pyrroline is a cyclic imine, whereas 2-pyrroline and 3-pyrroline are cyclic amines.
Many simple aromatic rings have trivial names. They are usually found as substructures of more complex molecules ("substituted aromatics"). Typical simple aromatic compounds are benzene, indole, and pyridine. [1] [2] Simple aromatic rings can be heterocyclic if they contain non-carbon ring atoms, for example, oxygen, nitrogen, or sulfur.
Alkaloids with partial pyrrolidine structure are usually sub-categorized based on their occurrence and biogenetic origin. Hygrin and cuscohygrin were isolated from the leaves of the coca shrub, [2] while (-)-codonopsinine was isolated from the woodland vine tiger bell.