Determination of Diastereoselectivity Experiment

Determination of Diastereoselectivity Experiment Jackson Nguyen Determination of Diastereoselectivity using Thermodynamic vs. Kinetic Controlled Reduction Procedures: A Reduction of 4-tert-butylcyclohexanone Introduction: The goal in this experiment was to oxidize 4-t-butylcyclohexanol to 4-t-butylcyclohexanone and reduce back to the original compound. Additionally, the goal was to analyze the ratio of the diastereomers and dictate the reasoning behind the ratios. Theory: In this experiment, three reactions total were performed. One of which was oxidation, and the other two were reduction. The overall result in this experiment was that 4-t-butylcyclohexanol was oxidized and reduced back to an alcohol through two different reactions that gave the same products. In order to oxidize 4-t-butylcyclohexanol, sodium hypochlorite was used, along with acetic acid. Acetic acid was used to protonate the hypochlorite which would then protonate the alcohol group of the reactant. As a result, the hydroxyl group with the extra hydrogen became a great leaving group, allowing hypochlorite, a nucleophile, to attack. This allowed a base, such as water, to deprotonate a hydrogen and create a double bond with the oxygen bond, which allowed the chlorine to leave. Overall, this reaction produced 4-t-butylcyclohexanone as the product. After the oxidized product was created, two different types of reduction were used to reduce the product created from oxidation. Two reagents used in each reduction reaction were sodium borohydride and aluminum isopropoxide. Both reagents would create similar products; however, the ratios of diastereomers were different. For sodium borohydride, the hydrogen would attack the carbonyl of 4-t-butylcyclohexonone and create a negative oxygen. Ethanol would act as a proton source in the solution and protonate the oxygen, which created a hydroxyl group. On the other hand, the reduction reaction that involved aluminum isopropoxide had a different mechanism. The carbonyl group of the 4-t-butylcyclohexonone would attack the partial positive aluminum due to the electronegativity of the oxygen. A hydrogen would attack the double bond of the carbonyl group and carry electrons over and allow the oxygen to have two pairs of electrons. As a result, the bulky group of the reactant would leave by an addition of hydrogen to the molecule, which created 4-t-butylcyclohexanol. Overall, both different reagents provided the same results. However, the ratio of diastereomers was determined by the structure of the reagents. In order convert the carbonyl group into an alcohol, a bond must be formed at 107Â ° angle. By looking at the structure of the hexane ring, the molecule can be attacked at two different sides. On one side, there were hydrogen that can provide steric hindrance; whereas, the other side would be free. Aluminum isopropoxide was a bulky group that will not likely to attack the 4-t-butylcyclohexanone at the side that has hydrogen. Hence, it would attack the side that had greater room. As a result, there was a higher ratio of an axial attack, compared to an equatorial attack of hydrogen. On the other hand, sodium borohydride was not a bulky group; thus, the ratio of axial and equatorial attacks would be more equal. Mechanism: Results: Part A: Part B: Part C: Discussion: The three reactions completed during the experiment were successful. By doing a TLC test every several minutes helped indicate the completion of the reactions and ensured that no reactant were present. The first two parts that required TLC testing showed the comparison between the starting material and the reaction mixture. Since TLC was based on polarity and the distance traveled, the completion of the reaction were focused on the distance of the spots and whether the initial spot disappeared after the reaction took place. The two main compounds were 4-t-butylcyclohexanol and 4-t-butylcyclohexanone. In order to analyze these two compounds, the polarity between them was different. The former compound had an alcohol group that was able to form hydrogen bonds; whereas, the latter compound cannot. Therefore, the former compound was more polar than the latter. In the case of the TLC testing, 4-t-butylcyclohexanone that was created from oxidation in part A, would travel farthe r on the TLC plate. Indicated in the data obtained, no reactant was left after the reaction, which indicated the completion of oxidation. On the other hand, the TLC test in Part B showed the same result. The product, 4-t-butylcyclohexanol was expected to travel less due to its polarity. Also, the final result showed that no reactant was present, indicated by the absence of the spot compared to the spot of the starting material. On another note, isopropyl alcohol was used to eliminate the excess of hypochlorite in Part A. By reacting hypochlorite and isopropyl alcohol, acetone and water were produced. Hence, hypochlorite was used to oxidize isopropyl alcohol in order to create acetone, which was a solvent that would interfere with the reaction; thus, it provided no harm and affect the results. The percent yield was decent for part A and was low for Part B and C. Possible reasoning for this could be that the products were lost during the extraction. It was not likely that the issue resided in the reaction itself because TLC testing indicated that all the reactants were used up. Hence, it was more likely that the extraction process may account for the loss of products. On another note, the ratio of trans/cis of the commercially obtained alcohol mixture seemed to be 1:3. Additionally, the standard ratios of the stereoisomers were almost the same compared to the HNMR spectrums obtained from the experiment. Since the ratio was 1:3, the method most likely used to synthesize the 4-t-butylcyclohexanol was the Meerwein-Pondorff-Verley Reduction. Sources of Errors: No major errors occurred during the experiment. One possible error that may account for the low recover of product would be the extraction. The extraction process went too fast, which may cause some products to be lost in the aqueous layer. However, the aqueous layer was extracted once more, which can minimize the loss of products. This was a possibility. Conclusion and Future Experiments: The results from the experiment concluded that Meerwein-Pondorff-Verley Reduction was the method used to synthesize the commercially obtained 4-t-butylcyclohexanol. Additionally, the products from reactions were successfully obtained from the completed reactions. Future experiments would include multiple attempts of the reactions in order to obtain a higher yield. Although, the results concluded the exact method used, more HNMR spectrums from additional experiments would provide credibility.

Analysis: Ernest Hemingway’s The Indian Camp Essay

The short story â€Å"Indian Camp† is written by Ernest Hemingway. It is written in 1921 and takes place in North America. â€Å"Indian Camp† is about a young boy named Nick, who travels with his father and Uncle George to an Indian Camp to help an Indian girl, who has been in a painful labor for two days. Nick’s father performs a very primitive cesarean, and in meantime the woman’s husband commits suicide by cutting his throat. My intention with this essay is first to make a charactersation of the most important characters of the story. Afterwards I would like to make a short analysis of the structure, narrator and language. And at last I intend to make an interpretation of the theme of â€Å"Indian Camp†. The main character of the story is Nick, and the description of him is made implicit. We know that he is a boy, who has a great relationship with his father: â€Å"Nick lay back with his father’s arm around him. † p. 1, l. 9. He is a young boy, about 8-10 years, because he is old enough to see the cesarean, but not the suicide. Nick is very brave, because he tackles the whole situation without crying and screaming. He thinks a lot and reflex on life, which is seen in the end, when he keeps asking about life and death. Nick is a complex character, because he goes through a development. In the beginning of the story he is sitting next to his father in the stern of the boat, and he doesn’t really know what a birth is, but in the end he is sitting in front of his father in the boat and is sure about what life is. Nick’s father is a flat character. He is middle-age since he has a son and a long education. He is proud of being a doctor, which is seen, when he teaches Nick about the birth. He cares a lot about his son, because he apologize him for taking him to the Indian Camp. He wants to avoid making him nervous, so he only tells him a few necessary things about the trip. Uncle George doesn’t have an active role in the story. But it seems as if he has a friendly relationship with the Indians, because he is already in the camp in the beginning of the story, and he stays there after the birth. There are many signs, that he might be the father of the baby. He stands next to the woman under the birth, and when she bites him, she smiles. Her husband commits suicide. He was maybe ashamed of his wife being together with another man. Another sign could be, that in America they have a tradition that you hand out a cigar, when you become a father. â€Å"Uncle George gave both the Indians cigars. † p. 2, l. 3. Ernest Hemingway choice of narrator and languages is focused by, that we have to think self and read between the lines. He has used a 3th person omniscient narrator seen from Nick’s point of view. But sometimes the narrator changes to someone else’s point of view: Nick’s father is not â€Å"the father† but suddenly â€Å"the doctor†. Uncle George looked at his arm. † p. 4, l. 10. Nick doesn’t see this, because he isn’t in the room. The language in â€Å"Indian Camp† is objective. There isn’t used many adjectives and there is much direct speak. The whole story starts in a boat and ends in a boat. It has the structure: home-out-home, where there at home is cosmos and out chaos. Nick’s goes through his development, when he is out in chaos. The story starts in media-res and it has an open ending. Indian Camp† has many themes. Growing up is a good theme for this story, because Nick goes through the development from child to an adult. It could also be life and death, as a man dies and a baby is born. Another theme could be the bond between Nick and his father and how it clearly changes after the suicide. His father sees how important it is to protect the one you love and therefore apologizes to Nick. Ernest Hemingway’s short story is about how a child deals the â€Å"real tough† life and also about the secession process from parents and develops.

Guy De Maupassant s Life - 1179 Words

Guy De Maupassant was born August 5, 1850, in Chà ¢teau de Miromesnil, France (The Famous People, Guy de Maupassant), when he was young his parents got divorced and after that, his father left, denying him a chance to develop a relationship with his son. He started school with a religious education but, after getting expelled on purpose he pursued a bachelor s degree at Lycà ©e at Le Havre (World History: The Modern Era, Guy de Maupassant). One of his most well known stories is The Necklace. In this story the main character Mme. Loisel has always wished that she had a better life, but she didn’t so she settled for the best that she could, which was a clerk in the Department of Education. One day her husband receives an invitation to a party†¦show more content†¦In his early career, he met many famous authors that were friends with Flaubert and they helped him to improve his work (World History: The Modern Era, Guy de Maupassant). Also due to his connections in the w riting world, he became an instant success as soon as he was published. People that read his works usually viewed him as French writer Guy de Maupassant is famous for his short stories, which paint a fascinating picture of French life in the 19th century (Biography.com, Guy de Maupassant) He became famous immediately but, it is debated whether his success was just based on his connections or because of his actual talent and special writing quirks that made him stand out as a writer. His work proved to be very popular due to his unique take on life and his â€Å"whiplash† endings that left the readers asking why(Encyclopedia of World Biography, Guy de Maupassant). The majority of his stories were categorized into sections, the Franco-Prussian War, the Norman peasantry, the bureaucracy, life on the banks of the Seine, the emotional problems of the different classes. All of his stories were based on what he had experienced, and these things had happened to him in one way or another. His writing was also considered to be put in the genre of naturalism. Naturalism is a style of writing based on an accurate depiction of real life. One of the most important influences to his writing, specifically in The Necklace was his parents divorce. After his parents gotShow MoreRelatedLiteray Analysis of The Necklace1155 Words   |  5 Pageshumans nature of greed. Guy De Maupassant, the author of The Necklace, perfectly shows how greed can lead to bad outcomes in the short story. Guy De Maupassant, one of the fathers of the short story, was born on August 5th 1850. A quote representing the legacy of Maupassant French writer of short stories an novels of the naturalists school who is by general agreement the greatest french short story writers(Bennet). In his short story, The Necklace, Maupassant focuses mostly on greed.Read MoreAnalysis Of The Necklace1358 Words   |  6 Pages â€Å"The Necklace† Analysis Plot Analysis - The plot analysis of (Exposition) â€Å"The Necklace† by Guy de Maupassant, take place in the late 1800s when Mathilde Loisel and her husband decides to go to a ball. The importance of the place is so you can fully appreciate how royal Mathilde is supposed to be at the ball, and let me tell you, she pulls it off. She was the most beautiful woman there, but surprisingly it wasn t the necklace that made her shineRead MoreA Wasteful Fashion in The Necklace by Guy de Maupassant1149 Words   |  5 PagesTen years of life used to pay back a debt that was worth ten thousand dollars. Was it worth it? Guy de Maupassant was a popular French writer who is known as one of the fathers of modern short stories. Many of Maupassant’s stories are set during the Franco-Prussian War of the 1870’s. Maupassant ended up writing about three hundred short stories, six novels, three travel books, and one volume of verse. In his short story, ‘The Necklace’, th e main character, Mathilde Loisel, feels as if she shouldRead MoreTheme of Reality vs. Appearances in â€Å"the Necklace†1617 Words   |  7 PagesAlbert Guy de Maupassant was born on August 5, 1850 in the chateau de Miromesnil near Dieppe, Normandy. He lived in Fecamp, France until age twelve (when his parents separated) then moved with his mother to a villa in Etretat, France. Home-schooled, except for a brief stay at a boarding school when he was thirteen, Maupassant ran free for most of his school years. Maupassant attended university in Paris, where he began to study law, and then served in the army in the Franco-Prussian war. Guy de Maupassant’sRead MoreAnalysis Of Anton Chekhov s The Husband And The Student 1264 Words   |  6 Pagescalled, a life as it is. He illustrates an everyday realism. He does not use big subjects, no larger than life s characters and no longer than life s emotions. In the stories The Husband and The Student it is a subject matter of straight forward and ordinary. An example in The Husband is how he resents his wife of having a good time and tries to ruin it. The husband was not feeling jealous and his wife is not frightened by him. It is like a everyday situation. The tax-collector s night doesRead MoreThe Necklace by Guy De Maupassant1367 Words   |  6 Pagesâ€Å"Being Honest is Always Best† Telling the truth will always prevent future conflicts. Author Guy De Maupassant who lived from 1850 to 1893 proves in the story of â€Å"The Necklace,† that no matter how bad a situation is, speaking with the truth is always best. Now, this author does not prove this theme directly. Instead, throughout various situations in the story the main characters are faced with a long-term conflict because decisions were not made with honesty. Mathilde and Loisel who is her husbandRead MoreSimilarities Between The Interlopers And Guy De Maupassant1666 Words   |  7 PagesIn both H.H. Munro’s â€Å"The Interlopers† and Guy de Maupassant’s â€Å"A Father’s Confession†, all actions, from family feuds to killing a child, have consequences like guilt and regret on the human race as a whole. â€Å"The Interlopers† captures the results caused from an argument that developed into a full-blown family feud, while â€Å"A Father’s Confessionâ €  shows the readers the impacts of killing a child, purposely or not. Secrets and grudges are common human tendencies, playing an enormous role in the socialRead MoreAnalysis Of Guy De Maupassant s `` The Necklace ``980 Words   |  4 PagesGuy De Maupassant s, The Necklace, is a short story about Mathilde Loisel, a middle-class wife, who is dissatisfied with her life and believes that she was meant to live as an upper-class woman. When invited to her husband s ball, she manipulates her way into getting a new dress and borrows her friend s diamond necklace. After the ball, she discovers the necklace is gone. Both Malthilde and her husband delay returning the lost necklace, and secretly buy a replica. They both struggle ten yearsRead MoreThe Necklace By Guy De Maupassant1381 Words   |  6 Pagesusing imagery. Two examples of these short stories are â€Å"The Necklace† by Guy de Maupassant and â€Å"The Secret Life of Walter Mitty† by James Thurber. â€Å"The Nec klace† was about a materialistic woman who faced consequences because of her envious personality and â€Å"The Secret Life of Walter Mitty† was about a man who experienced daydreams randomly throughout the day. Although both short stories used literary elements, Guy de Maupassant utilized them for readers to understand and enjoy the story more than JamesRead MoreSummary Of The Jewelry Essay782 Words   |  4 Pages True and False The Jewelry, which Maupassant wrote in the late eighteen hundreds. His writings are of everyday life situations that reveal hidden sides to people. The story of The Jewelry is set in 1833 in Paris. M. Lantin is the protagonist, and he is a seventeenth-century character in Guy De Maupassant s story. The story is used the third person narrative to describe a wife s deception and a husband s realization. M. Lantin was the chief accountant in the office