When there are two functional groups of unequal reactivity within a molecule, the more reactive group can be made to react alone, but it may not be possible to react the less reactive functional group selectively.
A group the use of which makes possible to react a less reactive functional group selectively in presence of a more reactive group is known as protecting group.
A protecting group blocks the reactivity of a functional group by converting it into a different group which is inert to the conditions of some reaction(s) that is to be carried out as part of a synthetic route
Contents includes at least three strategies of synthesis for each of three, four, five and six membered heterocylic ring with one or two heteroatoms. One mechanism described out of the three strategies. Few name reactions are described and the other are simple synthetic methods. This presentation was prepared for the partial fulfillment of Master of Pharmacy. The content was taken from the various books, mentioned in slide with the title of references.
IMPORTANT NAMED REACTIONS in Organic synthesis with Introduction, General Mechanism, and their synthetic application covering more than 20 named reactions in it.
Protection and deprotection of functional groups and it application in organi...ScifySolution
Protection of amine, acid, alcohol, ketone, aldehyde important for organic synthesis here we are providing complete study notes on it.
visit scifysolution.com for more notes
It is an intramolecular rearrangement reaction in which the 1,2-migration of silyl group from carbon to oxygen under basic conditions.It involves the formation of a pentacoordinate siliconintermediate.Discovered by Adrian Gibbs Brook in 1958.
PROTECTINGANDBDEPROTECTING GROUPS IN ORGANIC SYNTHESIS [M.PHARM]Shikha Popali
THE PROTECTING GROUPS USED FOR THE API TO PROTECT THEM TO DEGRADE AND COMBINE WITH IT WHEN THE API GET RELEASE THE PROTECTING GROUP GET DETACH AND REMOVE OUT.
Contents includes at least three strategies of synthesis for each of three, four, five and six membered heterocylic ring with one or two heteroatoms. One mechanism described out of the three strategies. Few name reactions are described and the other are simple synthetic methods. This presentation was prepared for the partial fulfillment of Master of Pharmacy. The content was taken from the various books, mentioned in slide with the title of references.
IMPORTANT NAMED REACTIONS in Organic synthesis with Introduction, General Mechanism, and their synthetic application covering more than 20 named reactions in it.
Protection and deprotection of functional groups and it application in organi...ScifySolution
Protection of amine, acid, alcohol, ketone, aldehyde important for organic synthesis here we are providing complete study notes on it.
visit scifysolution.com for more notes
It is an intramolecular rearrangement reaction in which the 1,2-migration of silyl group from carbon to oxygen under basic conditions.It involves the formation of a pentacoordinate siliconintermediate.Discovered by Adrian Gibbs Brook in 1958.
PROTECTINGANDBDEPROTECTING GROUPS IN ORGANIC SYNTHESIS [M.PHARM]Shikha Popali
THE PROTECTING GROUPS USED FOR THE API TO PROTECT THEM TO DEGRADE AND COMBINE WITH IT WHEN THE API GET RELEASE THE PROTECTING GROUP GET DETACH AND REMOVE OUT.
Protecting group (PG) is a small molecule, to mask temporarily the a specific functional group of a molecule from undergoing reaction, allowing the rest of the functional groups present in the molecule to react without affecting the original reactivity and leave from the host molecule without affecting the rest of the functional groups.
The addition of protecting groups to functional groups is termed ‘protection’ and removal of protecting group is ‘deprotection’.
Effect of substituents and functions on drug structure activity relationshipsOmar Sokkar
The replacement, in an active molecule, of a hydrogen atom by a substituent (alkyl, halogen, hydroxyl, nitro, cyano, alkoxy, amino, carboxylate, etc.) or a functional group can deeply modify The potency, The duration, Perhaps even the nature of the pharmacological effect.
June 3, 2024 Anti-Semitism Letter Sent to MIT President Kornbluth and MIT Cor...Levi Shapiro
Letter from the Congress of the United States regarding Anti-Semitism sent June 3rd to MIT President Sally Kornbluth, MIT Corp Chair, Mark Gorenberg
Dear Dr. Kornbluth and Mr. Gorenberg,
The US House of Representatives is deeply concerned by ongoing and pervasive acts of antisemitic
harassment and intimidation at the Massachusetts Institute of Technology (MIT). Failing to act decisively to ensure a safe learning environment for all students would be a grave dereliction of your responsibilities as President of MIT and Chair of the MIT Corporation.
This Congress will not stand idly by and allow an environment hostile to Jewish students to persist. The House believes that your institution is in violation of Title VI of the Civil Rights Act, and the inability or
unwillingness to rectify this violation through action requires accountability.
Postsecondary education is a unique opportunity for students to learn and have their ideas and beliefs challenged. However, universities receiving hundreds of millions of federal funds annually have denied
students that opportunity and have been hijacked to become venues for the promotion of terrorism, antisemitic harassment and intimidation, unlawful encampments, and in some cases, assaults and riots.
The House of Representatives will not countenance the use of federal funds to indoctrinate students into hateful, antisemitic, anti-American supporters of terrorism. Investigations into campus antisemitism by the Committee on Education and the Workforce and the Committee on Ways and Means have been expanded into a Congress-wide probe across all relevant jurisdictions to address this national crisis. The undersigned Committees will conduct oversight into the use of federal funds at MIT and its learning environment under authorities granted to each Committee.
• The Committee on Education and the Workforce has been investigating your institution since December 7, 2023. The Committee has broad jurisdiction over postsecondary education, including its compliance with Title VI of the Civil Rights Act, campus safety concerns over disruptions to the learning environment, and the awarding of federal student aid under the Higher Education Act.
• The Committee on Oversight and Accountability is investigating the sources of funding and other support flowing to groups espousing pro-Hamas propaganda and engaged in antisemitic harassment and intimidation of students. The Committee on Oversight and Accountability is the principal oversight committee of the US House of Representatives and has broad authority to investigate “any matter” at “any time” under House Rule X.
• The Committee on Ways and Means has been investigating several universities since November 15, 2023, when the Committee held a hearing entitled From Ivory Towers to Dark Corners: Investigating the Nexus Between Antisemitism, Tax-Exempt Universities, and Terror Financing. The Committee followed the hearing with letters to those institutions on January 10, 202
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
Unit 8 - Information and Communication Technology (Paper I).pdfThiyagu K
This slides describes the basic concepts of ICT, basics of Email, Emerging Technology and Digital Initiatives in Education. This presentations aligns with the UGC Paper I syllabus.
How to Make a Field invisible in Odoo 17Celine George
It is possible to hide or invisible some fields in odoo. Commonly using “invisible” attribute in the field definition to invisible the fields. This slide will show how to make a field invisible in odoo 17.
Synthetic Fiber Construction in lab .pptxPavel ( NSTU)
Synthetic fiber production is a fascinating and complex field that blends chemistry, engineering, and environmental science. By understanding these aspects, students can gain a comprehensive view of synthetic fiber production, its impact on society and the environment, and the potential for future innovations. Synthetic fibers play a crucial role in modern society, impacting various aspects of daily life, industry, and the environment. ynthetic fibers are integral to modern life, offering a range of benefits from cost-effectiveness and versatility to innovative applications and performance characteristics. While they pose environmental challenges, ongoing research and development aim to create more sustainable and eco-friendly alternatives. Understanding the importance of synthetic fibers helps in appreciating their role in the economy, industry, and daily life, while also emphasizing the need for sustainable practices and innovation.
Read| The latest issue of The Challenger is here! We are thrilled to announce that our school paper has qualified for the NATIONAL SCHOOLS PRESS CONFERENCE (NSPC) 2024. Thank you for your unwavering support and trust. Dive into the stories that made us stand out!
The French Revolution, which began in 1789, was a period of radical social and political upheaval in France. It marked the decline of absolute monarchies, the rise of secular and democratic republics, and the eventual rise of Napoleon Bonaparte. This revolutionary period is crucial in understanding the transition from feudalism to modernity in Europe.
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The Roman Empire A Historical Colossus.pdfkaushalkr1407
The Roman Empire, a vast and enduring power, stands as one of history's most remarkable civilizations, leaving an indelible imprint on the world. It emerged from the Roman Republic, transitioning into an imperial powerhouse under the leadership of Augustus Caesar in 27 BCE. This transformation marked the beginning of an era defined by unprecedented territorial expansion, architectural marvels, and profound cultural influence.
The empire's roots lie in the city of Rome, founded, according to legend, by Romulus in 753 BCE. Over centuries, Rome evolved from a small settlement to a formidable republic, characterized by a complex political system with elected officials and checks on power. However, internal strife, class conflicts, and military ambitions paved the way for the end of the Republic. Julius Caesar’s dictatorship and subsequent assassination in 44 BCE created a power vacuum, leading to a civil war. Octavian, later Augustus, emerged victorious, heralding the Roman Empire’s birth.
Under Augustus, the empire experienced the Pax Romana, a 200-year period of relative peace and stability. Augustus reformed the military, established efficient administrative systems, and initiated grand construction projects. The empire's borders expanded, encompassing territories from Britain to Egypt and from Spain to the Euphrates. Roman legions, renowned for their discipline and engineering prowess, secured and maintained these vast territories, building roads, fortifications, and cities that facilitated control and integration.
The Roman Empire’s society was hierarchical, with a rigid class system. At the top were the patricians, wealthy elites who held significant political power. Below them were the plebeians, free citizens with limited political influence, and the vast numbers of slaves who formed the backbone of the economy. The family unit was central, governed by the paterfamilias, the male head who held absolute authority.
Culturally, the Romans were eclectic, absorbing and adapting elements from the civilizations they encountered, particularly the Greeks. Roman art, literature, and philosophy reflected this synthesis, creating a rich cultural tapestry. Latin, the Roman language, became the lingua franca of the Western world, influencing numerous modern languages.
Roman architecture and engineering achievements were monumental. They perfected the arch, vault, and dome, constructing enduring structures like the Colosseum, Pantheon, and aqueducts. These engineering marvels not only showcased Roman ingenuity but also served practical purposes, from public entertainment to water supply.
2. I wish to convey my sincere regards and thanks to Dr.
Renu Gupta, Head Department of Chemistry Lucknow
Christian P.G College, Lucknow for her keen interest,
encouragement and fruitful suggestions and for providing
library facilities.
I would like to place on record my deep gratitude to Mr.
Mayank Joseph under whose guidance this project entitled
“Protecting Groups In Organic Synthesis ” is being
submitted, but for the constant support and encouragement
at every stage, it would not have been possible complete this
study.
My sincere thanks are to Dr. Stuti Gupta & Dr. Abhas
Asthana for their co-operation during the completion of the
project.
Apoorva Rastogi
5. When there are two functional groups of unequal reactivity
within a molecule, the more reactive group can be made to
react alone, but it may not be possible to react the less
reactive functional group selectively.
A group the use of which makes possible to react a less
reactive functional group selectively in presence of a more
reactive group is known as protecting group.
A protecting group blocks the reactivity of a functional group
by converting it into a different group which is inert to the
conditions of some reaction(s) that is to be carried out as part
of a synthetic route
6. When we choosing a suitable protecting group, the
following features must be considered :-
◦ Cheap and commercially available.
◦ Simple to put in high yield.
◦ Stable to reaction conditions.
◦ Easy to remove in high yield
7. ◦ Protection of Alcohols.
◦ Protection of Carbonyl Groups in Aldehyde And Ketones.
◦ Protection of Carboxylic acid.
◦ Protection of amines.
11. Acetals Or Ketals As Protecting Groups For Alcohols
Ether As Protecting Groups For Alcohals
Ester As Protecting Groups For Alcohals
12.
13. Acelals or ketals not only serve as useful protecting groups
for aldehydes and ketones but they also find widespread
use in the protection of alcohols.
Commonly used ketals include Tetrahydropyranyl (THP)
derivatives, methoxyethoxymethyl (MEM) derivative
and methoxymethyl (MOM) derivative.
Acetals / ketals are simply removed by treatment with
aqueous acid.
14.
15.
16.
17. Alcohols may be simply converted to ethers by
nucleophilic attack on a suitable alkyl halide.
Ethers are stable to basic and mildly acidic
conditions; they do not react with oxidizing /
reducing agents and are inert to organo-metallic
reagents. However, this stability means that many
others are not easily cleaved to their parent alcohol
under mild conditions. Therefore, only certain
ethers, which are easily cleaved under mild
conditions, are commonly used as protecting groups
for alcohols.
18. Benzyl ether which are converted to alcohols under
neutral conditions by catalytic hydrogenolysis.
20. Tri-phenylmethyl group is the most important
for the protection of 1°-alcoholic group. Only 1°-
alcohols react at a useful rate with trityl-chloride in
pyridine so selective protection of primary hydroxyl
groups is possible.
26. Cis 1, 2 diols and cis and trans-1,3 diols can be
protected as cyclic acetals and ketals (e.g., dioxlanes
and dioxanes) or cylic ortho esters that are cleaved
by acidic hydrolysis or as cylic esters (e.g,
carbonates) that are cleaved by basic hydrolysis.
Cyclic ortho esters are more readily cleaved by acidc
hydrolysis than cyclic acetals or ketals.
33. The acetal / ketals protective group is introduced by
treating the carbonyl compounds with an alcohol, an
ortho-ester, or a diol in the presence of a Lewis acid as
catalyst.
Acetals / ketals are stable to strong aqueous bases,
nucleophilic reducing agents, organometallic reagents,
oxidation under non-acidic conditions, Na or Li/NH3
reductions.
Acetals / ketals are cleaved by acid-catalyzed hydrolysis
34. General order of reactivity of various carbonyl
groups (probably due to the steric effect).
1,3-dioxanes (six-membered ring) hydrolyze faster
than the corres-ponding 1,3-dioxolanes (five-
membered ring acetal)
35. Acyclic acetals is prepared by the reaction of
aldehyde with monohydric alcohal in the presence
of dry HCl.
36. Acylic ketones cannot be prepared with monohydric
alcohols under the same condition of acetals
formation because of the unfavourable entropy,
which the equillbrium towards the ketones So
acyclic ketals are prepared by the reaction of
ketones with ethylorthoformate in presence of the
NH4Cl.
37.
38. Thioacetals / thioketals are quite stable toward
hydrolysis; there is no special need to remove the
H2O formed during the reaction.
39.
40.
41.
42. Protecting groups for carboxylic acids are used to
avoid reaction of the acidic -COOH hydrogen with
bases and nucleophiles or to prevent nucleophilic
additions at the carbonyl carbon.
43. Most common group for the protection of
acid is ester.
44.
45.
46.
47.
48.
49.
50.
51.
52. The basic problem of peptide synthesis is one of
protecting the amino group. In bringing about
interaction between the carboxyl group of one
amino acid and the amino group of a different amino
acid, one must prevent interaction between the
carboxyl group and the amino group of the same
amino acid. In preparing glycylalanine, for example,
one must prevent the simultaneous formation of
glycylglycine. Reaction can be forced to take place in
the desired way by attaching to one amino acid a
group that renders the NH2 unreactive.
53.
54.
55.
56.
57.
58.
59. Amides are readily prepared from an amine and an
acid chloride or anhydride. These are relatively
more stable compounds that, classically, are cleaved
by heating in strongly acidic or basic solutions.
60.
61.
62.
63.
64.
65. [1] Singh, J ; Yadav, L.D.S; Organic Synthesis;Pragati
Publicaton; thirteenth edition- 2017; pp. 696-
721.
[2] Kar, K.R.; Application of Redox and Reagents
in Organic Synthesis; New Central Book
Agency (P) Ltd; volume-1; pp 376-385.
[3] Clayden, J; Greeves, N; Warren, S; Wothers, P;
Organic Chemistry; pp 633-637 & 657
66. [4] Hanson, J.R.; Protecting Groups in Organic
Synthesis; Sheffield Academic Press; pp 8- 80.
[5] Morrison, R.T.; Boyd R.N.; Organic Chemistry;
Prentice-Hall of India Private Limited; Sixth Edition-
2002; pp. 1147
[6] March, J; Smith, M.B.; March’s Advanced
Organic Chemistry: Reactions, Mechanisms, and
Structure; Wiley Publication; Sixth Edition; pp
1271-1279
