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. [1] [2]
The structure of morphine is not particularly complex, however the electrostatic polarization of adjacent bonded atoms does not alternate uniformly throughout the structure. This "dissonant connectivity" makes bond formation more difficult and therefore significantly complicates any synthetic strategy that is applied to this family of molecules. [2]
The first morphine total synthesis, devised by Marshall D. Gates, Jr. in 1952 remains a widely used example of total synthesis. [3] This synthesis took a total of 31 steps and proceeded in 0.06% overall yield. The hydrocodone synthesis of Kenner C. Rice is one of the most efficient and proceeds in 30% overall yield in 14 steps. [4] At 9 steps, the Barriault route is the shortest to date, but contains a number of low-yielding steps and is racemic. [5]
Several other syntheses were reported, notably by the research groups of Evans, [6] Fuchs, [7] Parker, [8] Overman, [9] Mulzer-Trauner, [10] White, [11] Taber, [12] Trost, [13] Fukuyama, [14] Guillou, [15] Stork, [16] Magnus, [17] Smith, [18] and Barriault. [5]
Gates' total synthesis of morphine [3] provided a proof of the structure of morphine proposed by Robinson in 1925. [19] This synthesis of morphine features one of the first examples of the Diels-Alder reaction in the context of total synthesis. [3]
The Rice synthesis follows a biomimetic route and is the most efficient reported to date. A key step is the Grewe cyclization that is analogous to the cyclization of reticuline that occurs in morphine biosynthesis. [4]
Morphine is a strong opiate that is found naturally in opium, a dark brown resin in poppies. It is mainly used as a pain medication, and is also commonly used recreationally, or to make other illicit opioids. There are numerous methods used to administer morphine: oral; sublingual; via inhalation; injection into a muscle; by injection under the skin; intravenously; injection into the space around the spinal cord; transdermal; or via rectal suppository. It acts directly on the central nervous system (CNS) to induce analgesia and alter perception and emotional response to pain. Physical and psychological dependence and tolerance may develop with repeated administration. It can be taken for both acute pain and chronic pain and is frequently used for pain from myocardial infarction, kidney stones, and during labor. Its maximum effect is reached after about 20 minutes when administered intravenously and 60 minutes when administered by mouth, while the duration of its effect is 3–7 hours. Long-acting formulations of morphine are available as MS-Contin, Kadian, and other brand names as well as generically.
Thebaine (paramorphine), also known as codeine methyl enol ether, is an opiate alkaloid, its name coming from the Greek Θῆβαι, Thēbai (Thebes), an ancient city in Upper Egypt. A minor constituent of opium, thebaine is chemically similar to both morphine and codeine, but has stimulatory rather than depressant effects. At high doses, it causes convulsions similar to strychnine poisoning. The synthetic enantiomer (+)-thebaine does show analgesic effects apparently mediated through opioid receptors, unlike the inactive natural enantiomer (−)-thebaine. While thebaine is not used therapeutically, it is the main alkaloid extracted from Papaver bracteatum and can be converted industrially into a variety of compounds, including hydrocodone, hydromorphone, oxycodone, oxymorphone, nalbuphine, naloxone, naltrexone, buprenorphine, butorphanol and etorphine.
Organic synthesis is a special branch of chemical synthesis and is concerned with the intentional construction of organic compounds. Organic molecules are often more complex than inorganic compounds, and their synthesis has developed into one of the most important branches of organic chemistry. There are several main areas of research within the general area of organic synthesis: total synthesis, semisynthesis, and methodology.
The Robinson annulation is a chemical reaction used in organic chemistry for ring formation. It was discovered by Robert Robinson in 1935 as a method to create a six membered ring by forming three new carbon–carbon bonds. The method uses a ketone and a methyl vinyl ketone to form an α,β-unsaturated ketone in a cyclohexane ring by a Michael addition followed by an aldol condensation. This procedure is one of the key methods to form fused ring systems.
Longifolene is the common chemical name of a naturally occurring, oily liquid hydrocarbon found primarily in the high-boiling fraction of certain pine resins. The name is derived from that of a pine species from which the compound was isolated, Chemically, longifolene is a tricyclic sesquiterpene. This molecule is chiral, and the enantiomer commonly found in pines and other higher plants exhibits a positive optical rotation of +42.73°. The other enantiomer is found in small amounts in certain fungi and liverworts.
The article concerns the total synthesis of galanthamine, a drug used for the treatment of mild to moderate Alzheimer's disease.
Morphinan is the prototype chemical structure of a large chemical class of psychoactive drugs, consisting of opiate analgesics, cough suppressants, and dissociative hallucinogens, among others.
The Negishi coupling is a widely employed transition metal catalyzed cross-coupling reaction. The reaction couples organic halides or triflates with organozinc compounds, forming carbon-carbon bonds (C-C) in the process. A palladium (0) species is generally utilized as the metal catalyst, though nickel is sometimes used. A variety of nickel catalysts in either Ni0 or NiII oxidation state can be employed in Negishi cross couplings such as Ni(PPh3)4, Ni(acac)2, Ni(COD)2 etc.
Aporphine is an alkaloid with the chemical formula C17H17N. The IUPAC name of aporphine is 6-methyl-5,6,6a,7-tetrahydro-4H-dibenzo[de,g]quinoline. It is the core chemical substructure of the aporphine alkaloids, a subclass of quinoline alkaloids. It can exist in either of two enantiomeric forms, (R)-aporphine and (S)-aporphine.
In organic chemistry, the Schmidt reaction is an organic reaction in which an azide reacts with a carbonyl derivative, usually an aldehyde, ketone, or carboxylic acid, under acidic conditions to give an amine or amide, with expulsion of nitrogen. It is named after Karl Friedrich Schmidt (1887–1971), who first reported it in 1924 by successfully converting benzophenone and hydrazoic acid to benzanilide. The intramolecular reaction was not reported until 1991 but has become important in the synthesis of natural products. The reaction is effective with carboxylic acids to give amines (above), and with ketones to give amides (below).
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.
Heterocodeine (6-methoxymorphine) is an opiate derivative, the 6-methyl ether of morphine, and a structural isomer of codeine; it is called "hetero-" because it is the reverse isomer of codeine. Heterocodeine was first synthesised in 1932 and first patented in 1935. It can be made from morphine by selective methylation. Codeine is the natural mono-methyl ether, but must be metabolized for activity. In contrast the semi-synthetic mono-methyl ether, heterocodeine is a direct agonist. The 6,7,8,14 tetradehydro 3,6 methyl di-ether of morphine is thebaine.
Larry E. Overman is Distinguished Professor of Chemistry at the University of California, Irvine. He was born in Chicago in 1943. Overman obtained a B.A. degree from Earlham College in 1965, and he completed his Ph.D. in chemistry from the University of Wisconsin–Madison in 1969, under Howard Whitlock Jr. Professor Overman is a member of the United States National Academy of Sciences and the American Academy of Arts and Sciences. He was the recipient of the Arthur C. Cope Award in 2003, and he was awarded the Tetrahedron Prize for Creativity in Organic Chemistry for 2008.
The Stieglitz rearrangement is a rearrangement reaction in organic chemistry which is named after the American chemist Julius Stieglitz (1867–1937) and was first investigated by him and Paul Nicholas Leech in 1913. It describes the 1,2-rearrangement of trityl amine derivatives to triaryl imines. It is comparable to a Beckmann rearrangement which also involves a substitution at a nitrogen atom through a carbon to nitrogen shift. As an example, triaryl hydroxylamines can undergo a Stieglitz rearrangement by dehydration and the shift of a phenyl group after activation with phosphorus pentachloride to yield the respective triaryl imine, a Schiff base.
Twistane (IUPAC name: tricyclo[4.4.0.03,8]decane) is an organic compound with the formula C10H16. It is a cycloalkane and an isomer of the simplest diamondoid, adamantane, and like adamantane, is not very volatile. Twistane was named for the way its rings are permanently forced into the cyclohexane conformation known as the "twist-boat". The compound was first reported by Whitlock in 1962.
Marshall D. Gates Jr. (1915–2003) was an American chemist, holding the position of C.F. Houghton Professor of Chemistry at the University of Rochester. He was an organic chemist whose research was in the field of natural product synthesis. He is best known for publishing the first total synthesis of morphine in 1952.
The Saegusa–Ito oxidation is a chemical reaction used in organic chemistry. It was discovered in 1978 by Takeo Saegusa and Yoshihiko Ito as a method to introduce α-β unsaturation in carbonyl compounds. The reaction as originally reported involved formation of a silyl enol ether followed by treatment with palladium(II) acetate and benzoquinone to yield the corresponding enone. The original publication noted its utility for regeneration of unsaturation following 1,4-addition with nucleophiles such as organocuprates.
Salutaridinol is a modified benzyltetrahydroisoquinoline alkaloid with the formula C19H23NO4. It is produced in the secondary metabolism of the opium poppy Papaver somniferum (Papaveraceae) as an intermediate in the biosynthetic pathway that generates morphine. As an isoquinoline alkaloid, it is fundamentally derived from tyrosine as part of the shikimate pathway of secondary metabolism. Salutaridinol is a product of the enzyme salutaridine: NADPH 7-oxidoreductase and the substrate for the enzyme salutaridinol 7-O-acetyltransferase, which are two of the four enzymes in the morphine biosynthesis pathway that generates morphine from (R)-reticuline. Salutaridinol's unique position adjacent to two of the four enzymes in the morphine biosynthesis pathway gives it an important role in enzymatic, genetic, and synthetic biology studies of morphine biosynthesis. Salutaridinol levels are indicative of the flux through the morphine biosynthesis pathway and the efficacy of both salutaridine: NADPH 7-oxidoreductase and salutaridinol 7-O-acetyltransferase.
Rick L. Danheiser is an American organic chemist and is the Arthur C. Cope Professor of Chemistry at the Massachusetts Institute of Technology and Chair of the MIT Faculty. His research involves the invention of new methods for the synthesis of complex organic compounds. Danheiser is known for the Danheiser annulation and Danheiser benzannulation reactions.
The Hegedus indole synthesis is a name reaction in organic chemistry that allows for the generation of indoles through palladium(II)-mediated oxidative cyclization of ortho-alkenyl anilines. The reaction can still take place for tosyl-protected amines.
Morphine's synthesis remains a serious challenge to this day.