Saturday, April 27, 2013

My Journey Through Organic Chemistry

My Journey Through Organic Chemistry


1. The most valuable lesson learned from organic chemistry:

     Organic chemistry is the study of the structure, reactions, chemical and physical properties of organic compounds. However, as I reach my final week of the second semester of the two semester organic chemistry sequence at Campbellsville University I wonder how such a simple definition could turn into endless hours of studying topics that seem far beyond the reach of the basic definition of organic chemistry. There are many things that I have learned from organic chemistry that I would consider important. In the first semester of organic chemistry we learned the basic properties of chemical compounds such as acidity, basicity, polarity, hybridization, and inter and intra molecular bonding. In the first semester of organic chemistry lab we learned the basic techniques of simple and fractional distillation, recrystallization, and acid base extraction. We also learned how to apply our knowledge through conducting proton  NMR, and infrared spectroscopy at the University of Louisville to compounds we synthesized in our organic chemistry lab.

     In the second semester of organic chemistry we learned how to apply the foundation of knowledge acquired during the previous semester to reactions involving organic compounds. Some of the reactions studied in the second semester of organic chemistry was the fisher esterfication, diels-alder reaction,  aldol reaction, reduction reactions, and reactions of amides, amines, carboxylic acids just to name a few. During the second semester of organic chemistry lab we learned how to take the basic lab techniques acquired in the first semester and apply them to conducting various synthesis reactions and ultimately a final synthesis project using the product recovered from a previous experiment.

        Overall the most important thing I believe that I learned from taking organic chemistry was how to apply the knowledge apply from lecture and lab. The information I gained from taking organic chemistry was applicable to real world situations in terms of carrying out synthesis reactions in lab, determining how prescription drugs are synthesized, and observing the chemical reactions that affect the human physiology.  Also, analytical thinking was another important skill I took away from the course. Learning how to analyze the mechanisms of certain reactions helped to determine the possible products that could be formed from certain reactions and which reagents to use to produce certain products.

2.  The most difficult component of the course:

     The most difficult component of the first semester of organic chemistry was learning how to analyze proton and carbon NMR spectrum, and determining the stereochemistry of molecules. While most of the second semester of organic chemistry was reactions it was difficult to keep all of the reactions organized and to remember which reaction mechanism went with each reagent. In additon, applying the material learned in lecture to lab was difficult at times. Because, you had to take pieces of information gathered from lecture and apply them to the big picuture of performing the actual reactions studied in lecture to lab.

 
3. The most surprising element of the course:

          The most surprising element of the course the amount of material covered throughout both semesters of the two semester sequence. The amount of time required to be successful in the course is tremendous due to the difficulty level and amount of course material. In addition I was surpised with the amount of team work that went into performing lab experiments. Each member of lab brought their own unique outlook on experiments which made the material more understadable and fun to learn. The benefits of working together as a team were present in both the lab and lecture protions of organic chemistry.      

 
4. What are 5 keys to success for organic chemistry students?

1. Manage your time effectively and schedule a brief time to study the course material on a daily basis.

2. Do not procrastinate on assignments or studying for exams.

3. Learn the material now and it will help on future exams and more complex topics covered in the future.

4. Study in groups to get different perspectives on the material being covered.

5. Make a reaction notebook that summarizes reactions covered in both semesters of organic chemistry to study for the ACS and finals.
 

5.  ACS Exam

A) How well did the ACS exam correspond to the material covered in the course:

     I believe the ACS exam corresponded quite well with the material covered in both semesters of organic chemistry. While there were a few questions that were unfamiliar on the standardized test, I was familiar with most of the questions that were asked on the exam. I believe that I would have benefited from an overview of which reagents went with certain reactions before the exam. However, overall the material covered in both semesters of organic chemistry allowed me to be familiar with the material covered on the exam.  

B) What was the most challenging question on the ACS exam?

     The most challenging aspect of the ACS exam for me was remembering which products were formed from the reagents. In addition, I found the stereochemistry questions slightly challenging also. A sample question I found difficult on the ACS exam was : Reaction of D-(-)-ribose with sodium borohydride gives? With the correct answer being a meso compound.  

Monday, April 15, 2013

Biotin Synthesis

 
 

-----Biotin Synthesis-----

 
 

Common Names: Biotin, Vitamin B7, Vitamin H

IUPAC Name: 5-[(3aS,4S,6aR)-2-oxohexahydro-1H-thieno[3,4-d]imidazol-4-yl]pentanoic acid

Chemical Formula:C10H16N2O3S

Information: Biotin is vitamin B and a coenzyme.Biotin is am important supplement supports cellular function, metabolism, nervous system function, and also promotes healthy skin and nail growth. Biotin can be obtained from the diet in whole grains, eggs, and dairy products. However, synthetically produced biotin is absorbed better by the body.1
Synthesis Steps: There are a total of 11 steps in the synthesis of biotin. The reagents used in the synthesis of biotin are common reagents that can be purchased commercially. Steps 3,7, and 10 were discussed in 341-344.Step 3 of the synthesis of Biotin involves the reduction of a carboxylic acid using DIBAL-H. In step 7 the polar protic solvent tetrahydrofuran (THF) is used. In step 10 NaBH4 in DMF is used as a reducing agent.

Functional Groups Present: Carboxylic acid (-COOH), Sulfide(-S-), Amine (-NH-).

Step 3: Step 3 of the synthesis of biotin involves the reduction of a carboxylic acid. The reduction in step 3  uses the reagent diisobutylaluminum hydride (DIBAL-H) to reduce the RCOOR' group to RCHO. The reduction agent DIBAL-H is a mild reducing agent that reacts at low temperatures. In the reduction the H:- is donated from the DIBAL-H agent to the carboxylic acid of the compound.2

Scheme 1.1: Reaction Step 3.2 



Final Product:
Scheme 1.1: Final Product Biotin.3



History: The Roche company is a health care company that specializes in producing synthetic vitamins and their derivatives. The company was founded in 1896 by Fritz-Hoffman-La Roche.The company invests over 4 billion dollars annually in pharmaceutical research and development. Roche's goal is to create products and services to prevent, diagnose and treat a variety of illnesses. The company has four pharmaceutical locations, and six diagnostic centers across the United States.3   



References



1WebMD Vitamins and Supplements Lifestyle Guide. http://www.webmd.com/vitamins-and-supplements/lifestyle-guide-11/supplement-guide-biotin (accessed April 12, 2013).

2Smith, Janice. Organic Chemistry. Second Edition. McGraw Hill Higher Education, 2008.

3Roche Home Page. http://www.rocheusa.com/portal/usa (accessed April 12, 2013).
 
 



Wednesday, March 13, 2013

Amino Acid -Building Blocks of Life

Amino Acids - The Building Blocks of Life


Amino acids are one of the four major groups of biomolcules. Amino acids are joined together by peptide bonds to form polypeptides and proteins.3 Peptide bonds are formed through dehydration synthesis which removes two hydrogen atoms from the amino group and an oxygen atom from the carboxy group. Amino acids form proteins which can take the form of primary, secondary, tertiary, or quaternary proteins. Proteins cam be fibrous, or globular. Fibrous proteins provide structural support to the tissues and cells of the body. Globular proteins form enzymes and transport proteins which play a vital role in human physiology. The two amino acids analyzed in this post are asparagine and glutamine.
 

IUPAC name: Asparagine

 
 
ACD ChemScetch Image1
 
 
 
Common name: 2-Amino-3-carbamoylpropanoic acid

Letter codes: Asn (N). 2

Neutral amino acid

Formula: C4H8N2O3

Molecular weight: 123.12g/mol. 2

Hydrogen bonding: Hydrogen bonding occurs at the hydroxy group (-OH) of the amino acid.

Dipeptide bond site: Circled in chemscetch image
ACD ChemScetch Image1

 

IUPAC name: Glutamine

 
ACD ChemScetch Image1
 

 

 

 


Common name: 2-Amino-4-carbamoylbutanoic acid; (levo)glutamide

Letter codes: Gln (Q). 2

Neutral amino acid

Formula: C5H10N2O3

Molecular weight: 146.14g/mol. 2

Hydrogen bonding: Hydrogen bonding occurs at the hydroxy group (-OH) of the amino acid.

Dipeptide bond site: Circled on chemscetch image
ACD ChemScetch Image 1


References
1ACD ChemScetch Free Software.
 
Chemspider.com.http://www.chemspider.com/Chemical-Structure.149808.html?rid=bce62c1b-719e-42e9-a4de-b3539bc4932a
 
3Smith, Janice. Organic Chemistry. Second Edition. McGraw Hill Higher Education, 2008.
 
 

Thursday, February 14, 2013

Diels-Alder


Diels-Alder Synthesis of Albicanol

CHE 342
Megan Mier
Compound: Albicanol
     The compound albicanol is formed through a series of synthesis steps including a Diels-Alder reaction. The reaction involves a 1,3 diene and a dienophile alkene. A Diels-Alder reaction forms six membered rings. Three p bonds are broken in a Diels-Alder reaction and two new C-C bonds and one new C=C bond is formed. Diels-Alder reactions are concerted and initiated by heat. In order for the diene to react with the dienophile the diene must be in the s-cis conformation.
     Albicanol is a compound that is used in the production of pharmaceutical antifungal creams. The compound is synthesized from liverworts and mulluscs.3 The synthesis of albicanol yields an racemic mixture of enantioselective products.
IUPAC Name: [(1S,4aS,8aS)-5,5,8a-Trimethyl-2-methylenedecahydro-1-naphthalenyl]methanol.1
Chemical Formula: C15H26O
Structure: ACD/ChemSketch
 
 
 
 
 
 
 
 
 
 
Reaction Scheme: 
Diels-Alder Reactants-          
 
Image: ACD ChemSketch
 


 
 
 
 
 
 
 
References:
1ChemSpider. CSID:149808, http://www.chemspider.com/Chemical-Structure.149808.html (accessed 14:19, Feb 13, 2013)
 
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