Piperidine is an organic compound with the molecular formula (CH2)5NH. This heterocyclic amine consists of a six-membered ring containing five methylene bridges (–CH2–) and one amine bridge (–NH–). It is a colorless liquid with an odor described as objectionable, typical of amines. The name comes from the genus name Piper, which is the Latin word for pepper. Although piperidine is a common organic compound, it is best known as a representative structure element within many pharmaceuticals and alkaloids, such as natural-occurring solenopsins.
Sharpless asymmetric dihydroxylation is the chemical reaction of an alkene with osmium tetroxide in the presence of a chiral quinine ligand to form a vicinal diol. The reaction has been applied to alkenes of virtually every substitution, often high enantioselectivities are realized, with the chiral outcome controlled by the choice of dihydroquinidine (DHQD) vs dihydroquinine (DHQ) as the ligand. Asymmetric dihydroxylation reactions are also highly site selective, providing products derived from reaction of the most electron-rich double bond in the substrate.
Piperine, possibly along with its isomer chavicine, is the compound responsible for the pungency of black pepper and long pepper. It has been used in some forms of traditional medicine.
The chiral pool is a "collection of abundant enantiopure building blocks provided by nature" used in synthesis. In other words, a chiral pool would be a large quantity of common organic enantiomers. Contributors to the chiral pool are amino acids, sugars, and terpenes. Their use improves the efficiency of total synthesis. Not only does the chiral pool contribute a premade carbon skeleton, their chirality is usually preserved in the remainder of the reaction sequence.
The Pictet–Spengler reaction is a chemical reaction in which a β-arylethylamine undergoes condensation with an aldehyde or ketone followed by ring closure. The reaction was first discovered in 1911 by Amé Pictet and Theodor Spengler. Traditionally, an acidic catalyst in protic solvent was employed with heating; however, the reaction has been shown to work in aprotic media in superior yields and sometimes without acid catalysis. The Pictet–Spengler reaction can be considered a special case of the Mannich reaction, which follows a similar reaction pathway. The driving force for this reaction is the electrophilicity of the iminium ion generated from the condensation of the aldehyde and amine under acid conditions. This explains the need for an acid catalyst in most cases, as the imine is not electrophilic enough for ring closure but the iminium ion is capable of undergoing the reaction.
The Feist–Benary synthesis is an organic reaction between α-halo ketones and β-dicarbonyl compounds to produce substituted furan compounds. This condensation reaction is catalyzed by amines such as ammonia and pyridine. The first step in the ring synthesis is related to the Knoevenagel condensation. In the second step the enolate displaces an alkyl halogen in a nucleophilic aliphatic substitution.
Lupinine is a quinolizidine alkaloid present in the genus Lupinus of the flowering plant family Fabaceae. The scientific literature contains many reports on the isolation and synthesis of this compound as well as a vast number of studies on its biosynthesis from its natural precursor, lysine. Studies have shown that lupinine hydrochloride is a mildly toxic acetylcholinesterase inhibitor and that lupinine has an inhibitory effect on acetylcholine receptors. The characteristically bitter taste of lupin beans, which come from the seeds of Lupinus plants, is attributable to the quinolizidine alkaloids which they contain, rendering them unsuitable for human and animal consumption unless handled properly. However, because lupin beans have potential nutritional value due to their high protein content, efforts have been made to reduce their alkaloid content through the development of "sweet" varieties of Lupinus.
Tetrahydrothiophene is an organosulfur compound with the formula (CH2)4S. The molecule consists of a five-membered saturated ring with four methylene groups and a sulfur atom. It is the saturated analog of thiophene or the sulfur analog of THF. It is a volatile, colorless liquid with an intensely unpleasant odor. It is also known as thiophane, thiolane, or THT.
Mesembrine is an alkaloid present in Sceletium tortuosum (kanna). It has been shown to act as a serotonin reuptake inhibitor (Ki = 1.4 nM), and has also been found to behave as a weak inhibitor of the enzyme phosphodiesterase 4 (PDE4) (Ki = 7,800 nM). In an in vitro study published in 2015, researchers concluded that "a high-mesembrine Sceletium extract" may exert anti-depressant effects by acting as a monoamine releasing agent." As such, mesembrine likely plays a dominant role in the antidepressant effects of kanna. The levorotatory isomer, (−)-mesembrine, is the natural form.
Lobeline is a piperidine alkaloid found in a variety of plants, particularly those in the genus Lobelia, including Indian tobacco, Devil's tobacco, great lobelia, Lobelia chinensis, and Hippobroma longiflora. In its pure form, it is a white amorphous powder which is freely soluble in water.
4-Piperidone is an organic compound with the molecular formula OC(CH2)4NH. It can be viewed as a derivative of piperidine. 4-Piperidone is used as an intermediate in the manufacture of chemicals and pharmaceutical drugs. Substituted and dehydro derivatives of 4-piperidinone are intermediates in alkaloid syntheses.
Solenopsin is a lipophilic alkaloid with the molecular formula C17H35N found in the venom of fire ants (Solenopsis). It is considered the primary toxin in the venom and may be the component responsible for the cardiorespiratory failure in people who experience excessive fire ant stings.
Spirotryprostatin B is an indolic alkaloid found in the Aspergillus fumigatus fungus that belongs to a class of naturally occurring 2,5-diketopiperazines. Spirotryprostatin B and several other indolic alkaloids have been found to have anti-mitotic properties, and as such they have become of great interest as anti-cancer drugs. Because of this, the total syntheses of these compounds is a major pursuit of organic chemists, and a number of different syntheses have been published in the chemical literature.
Allopumiliotoxin 267A is a toxin found in the skin of several poison frogs of the family Dendrobates. It is a member of the class of compounds known as allopumiliotoxins. The frogs produce the toxin by modifying the original version, pumiliotoxin 251D. It has been tested on mice and found to be five times more potent than the former version. It has been produced synthetically through a variety of different routes.
Horsfiline is an oxindole alkaloid found in the plant Horsfieldia superba, which is used in traditional herbal medicine. It has analgesic effects and has been the subject of research both to produce it synthetically by convenient routes and to develop analogues and derivatives which may have improved analgesic effects.
Arylcyclohexylamines, also known as arylcyclohexamines or arylcyclohexanamines, are a chemical class of pharmaceutical, designer, and experimental drugs.
Synthesis of morphine-like alkaloids in chemistry describes the total synthesis of the natural morphinan class of alkaloids that includes codeine, morphine, oripavine, and thebaine and the closely related semisynthetic analogs methorphan, buprenorphine, hydromorphone, hydrocodone, isocodeine, naltrexone, nalbuphine, oxymorphone, oxycodone, and naloxone.
Lythranidine is a piperidine alkaloid that was first isolated from the plant Lythrum anceps. It contains a 17-membered cyclophane ring.
Strictamine is an alkaloid isolated from Alstonia scholaris.
Akuammicine is a monoterpene indole alkaloid of the Vinca sub-group. It is found in the Apocynaceae family of plants including Picralima nitida, Vinca minor and the Aspidosperma.
