ORGANIC CHEMI

ORGANIC SYNTHESIS PORTALS

DR ANTHONY MELVIN CRASTO Ph.D Synthesis , , , , , , , ,

http://newdrugapprovals.wordpress.com/drug-synthesis/

Advertisement

The Chemistry of Love

DR ANTHONY MELVIN CRASTO Ph.D ANTHONY MELVIN CRASTO, drugs, ORGANIC CHEMISTRY , , , , ,

There are a lot of chemicals racing around your brain and body when you’re in love. Researchers are gradually learning more and more about the roles they play both when we are falling in love and when we’re in long-term relationships. Of course, estrogen and testosterone play a role in the sex drive area . Without them, we might never venture into the “real love” arena.

That initial giddiness that comes when we’re first falling in love includes a racing heart, flushed skin and sweaty palms. Researchers say this is due to the dopamine, norepinephrine and phenylethylamine we’re releasing. Dopamine is thought to be the “pleasure chemical,” producing a feeling of bliss. Norepinephrine is similar to adrenaline and produces the racing heart and excitement. According to Helen Fisher, anthropologist and well-known love researcher from Rutgers University, together these two chemicals produce elation, intense energy, sleeplessness, craving, loss of appetite and focused attention. She also says, “The human body releases the cocktail of love rapture only when certain conditions are met and … men more readily produce it than women, because of their more visual nature.”

Researchers are using functional magnetic resonance imaging (fMRI) to watch people’s brains when they look at a photograph of their object of affection. According to Helen Fisher, a well-known love researcher and an anthropologist at Rutgers University, what they see in those scans during that “crazed, can’t-think-of-anything-but stage of romance” — the attraction stage — is the biological drive to focus on one person. The scans showed increased blood flow in areas of the brain with high concentrations of receptors for dopamine — associated with states of euphoria, craving and addiction. High levels of dopamine are also associated with norepinephrine, which heightens attention, short-term memory, hyperactivity, sleeplessness and goal-oriented behavior. In other words, couples in this stage of love focus intently on the relationship and often on little else.

Another possible explanation for the intense focus and idealizing view that occurs in the attraction stage comes from researchers at University College London. They discovered that people in love have lower levels of serotonin and also that neural circuits associated with the way we assess others are suppressed. These lower serotonin levels are the same as those found in people with obsessive-compulsive disorders, possibly explaining why those in love “obsess” about their partner.

 

 

Iron-Catalyzed Synthesis of Cyclopropyl Halides

DR ANTHONY MELVIN CRASTO Ph.D Synthesis , , ,

Thumbnail image of graphical abstract
Iron-Catalyzed Synthesis of Cyclopropyl Halides

ChemCatChem, Current Issue:January 2013

Volume 5, Issue 1

Sabine Grupe and Prof. Dr. Axel Jacobi von Wangelin

Article first published online: 4 JAN 2013 | DOI: 10.1002/cctc.201200740

Under a halo: Selective iron-catalyzed hydrodehalogenations of dibromo- and dichlorocyclopropanes are effectively realized with tBuMgCl as the reductant. The reactions proceed under mild conditions and exhibit superior selectivities to iron-free protocols, as no allenes are formed. The sequential combination of base-mediated dihalocyclopropanation and this mono-dehalogenation provides straightforward access to substituted monohalocyclopropanes.
the supporting info file gives syn and spectral properties

VITAMIN E VISITED

DR ANTHONY MELVIN CRASTO Ph.D ANTHONY MELVIN CRASTO, ORGANIC CHEMISTRY, Synthesis , , , ,

The α-tocopherol form of vitamin E

Vitamin E refers to a group of eight fat-soluble compounds that include both tocopherolsand tocotrienols.[1] There are many different forms of vitamin E, of which γ-tocopherol is the most common in the North American diet.[2] γ-Tocopherol can be found in corn oil, soybean oil, margarine and dressings.[3][4] In the North American diet, α-Tocopherol, the most biologically active form of vitamin E, is the second most common form of vitamin E. This variant of vitamin E can be found most abundantly in wheat germ oil, sunflower, and safflower oils.[4][5] It is a fat-soluble antioxidant that stops the production of reactive oxygen species formed when fat undergoes oxidation.[6][7][8]

  • Synthesis of Vitamin E

Vitamin E (CAS NO.: 59-02-9), with other names as 2(R),5,7,8-Tetramethyl-2-[4(R),8(R),12-trimethyltridecyl]-3,4-dihydro-2H-1-benzopyran-6-ol, could be produced through the following synthetic routes.

 Synthesis of Vitamin E
           Synthesis of Vitamin E
The chlorination of myrcene (I) with Cl2 in refluxing pentane gives the choromyrcene (II), and the hydrochlorination of (I) catalyzed by CuCl yields a mixture of geranyl/neryl chloride (III). The reductive coupling of (II) and (III) by means of Mg and CuCl affords beta-springene (IV), which is condensed with 2,3,6-trimethylhydroquinone (V) by means of cyclooctadienyl rhodium chloride dimer [RhCl(COD)]2 and K2CO3 in refluxing toluene to provide the adduct (VI). The cyclization of (VI) by means of MeAlCl2 of Ts-OH in refluxing hexane furnishes the tocotrienol (VII), which is finally hydrogenated with H2 over Pd/C in ethanol to give the target (rac)-vitamin E.

 References

  1. Brigelius-Flohe, B; Traber (1999). “Vitamin E: function and metabolism”. FASEB 13: 1145–1155.
  2. Traber, MG (1998). “The biological activity of vitamin E”. The Linus Pauling Institute. Retrieved 6 March 2011.
  3. Bieri, JG; Evarts (1974). “γ-Tocopherol: metabolism, biological activity and significance in human vitamin E nutrition”. American Journal of Clinical Nutrition 27 (9): 980–986. PMID 4472121.
  4. Brigelius-Flohé R, Traber MG (1 July 1999). “Vitamin E: function and metabolism”. FASEB J. 13 (10): 1145–55. PMID 10385606.
  5. Reboul E, Richelle M, Perrot E, Desmoulins-Malezet C, Pirisi V, Borel P (15 November 2006). “Bioaccessibility of carotenoids and vitamin E from their main dietary sources”. Journal of Agricultural and Food Chemistry 54 (23): 8749–8755. doi:10.1021/jf061818s.PMID 17090117.
  6. National Institute of Health (4 May 2009). “Vitamin E fact sheet”.
  7. Herrera; Barbas, C (2001). “Vitamin E: action, metabolism and perspectives”. Journal of Physiology and Biochemistry 57 (2): 43–56.doi:10.1007/BF03179812. PMID 11579997.
  8. Packer L, Weber SU, Rimbach G (2001). “Molecular aspects of α-tocotrienol antioxidant action and cell signalling”. Journal of Nutrition 131 (2): 369S–73S. PMID 11160563.

Peptide coupling reagents—1-{[1-(Cyano-2-ethoxy-2-oxoethylidenaminooxy)dimethyl­aminomorpholinomethylene]}methaneaminium hexafluo­rophosphate (COMU)

DR ANTHONY MELVIN CRASTO Ph.D ANTHONY MELVIN CRASTO, ORGANIC CHEMISTRY, Synthesis ,

 

Peptide coupling reagents are rapidly evolving in the last years from the classical carbodiimide methods to a second generation onium salts based reactives,[1] and nowadays the novel uronium-type reagents derived from Oxyma like 1-{[1-(Cyano-2-ethoxy-2-oxoethylidenaminooxy)dimethyl­aminomorpholinomethylene]}methaneaminium hexafluo­rophosphate (COMU) introduced by Albericio’s group. This third generation peptide coupling reagent is soluble and stable due to the presence of morpholin. By-products are water-soluble and easy to remove, making COMU an excellent choice as coupling reagent in solid- and liquid-phase peptide synthesis. In addition, COMU shows a less hazardous safety profile than benzotriazole-based reagents like HATU and HBTU, which exhibit unpredictable autocatalytic decomposition and therefore a higher risk of explosion, and cause allergic reactions. COMU gives better results than aza derivatives in the presence of only one equivalent of base, and no activation time is required reducing the common racemization problem. Further, the couplings can be monitored by advantageous visual or colorimetric reaction. Although commercially available, COMU can be prepared easily

Synlett 2012; 23(12): 1849-1850
DOI: 10.1055/s-0031-1290443

https://www.thieme-connect.de/ejournals/html/10.1055/s-0031-1290443

Julián Bergueiro Álvarez

  • Departamento de Química Orgánica, Universidad de Santiago de Compostela,  Spain,

see more on open access paper

https://www.thieme-connect.de/ejournals/html/10.1055/s-0031-1290443

copy paste link

 

BOMBYKOL REVIEW AND SYNTHESIS

DR ANTHONY MELVIN CRASTO Ph.D Synthesis , , ,

http://www.slideshare.net/anthonycrasto64/anthony-crasto-bombykol  IS THE LINK TO MY PRESENTATION

Bombykol is a pheromone released by the female silkworm moth to attract mates. Discovered by Adolf Butenandt in 1959, it was the first pheromone to be characterized chemically. Minute quantities of this pheromone can be used per acre of land to confuse male insects about the location of their female partners, it can thus serve as a lure in traps to effectively remove insects without spraying crops with large amounts of chemicals. Butenandt named the substance after the moth’s Latin name Bombyx mori.