Organizing Organic Chemistry: Biochemistry Reactions

By Jeongbin Park and EUNJOLEE

The "Biochemistry Reactions" edition focuses on organic reactions that take place under mild conditions, providing concepts that are more pertinent to biochemistry. It serves as an essential guide for students and professionals in organic chemistry, providing a comprehensive overview of both fundamental and advanced organic reactions. Designed to facilitate learning and practical application, this book bridges the gap between theoretical concepts and real-world practice.

• Language: English
• Publisher: 이즈그리민(izgrimean)
• Release date: Jun 14, 2024
• ISBN: 9791198708052

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Comments from Jeongbin Park

I opened a blog called Jeongbin’s Study Room to collect knowledge from many people. The enthusiasm for organic chemistry is still strong today, but a few years ago, it was significant, as organic chemistry was essential for various exams. Since studying organic chemistry in elementary, middle, and high school was rare, I anticipated a significant academic demand for organic chemistry. Therefore, since 2018, I have been sharing articles on organic chemistry on Jeongbin’s Study Room and communicating, correcting, and discussing with people. I have had many discussions online with medical professionals, pharmacists, lawyers, current teachers, and professors, among others. Now, as we welcome the new year 2024, I declare that the compilation of organic chemistry knowledge through collective intelligence is complete and I am publishing this book. I hope that this book can lower the barrier of organic chemistry as a field of study.

If you send the purchase receipt of the book to [e-mail], we will provide you with additional lecture materials and problem sets.

Ch. 1: Alcohols

Ch. 1: Alcohols

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1. Nomenclature

2. Physical Properties

3. Reactions

4. Synthesis Methods

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1. Nomenclature

⑴ There are IUPAC nomenclature and common names.

⑵ Alcohol (R-O-H) nomenclature

① Determine the longest carbon chain (ring) structure containing the alcohol as the parent structure.

② Number each carbon starting from the carbon closest to the -OH group in the carbon chain.

③ If there are substituents, name them in alphabetical order.

④ In cases of mixtures of alkyl, halo, alkene, and alkyne groups, the priority of functional groups is as follows:

○ -OH > Alkene > Alkyne > Halogen

⑤ Common names: The examples are as follows:

○ Propyl alcohol

○ Butyl alcohol

○ Sec-butyl alcohol

○ Tert-butyl alcohol

○ Isobutyl alcohol

○ Neopentyl alcohol

⑶ Polyols (polyalcohols): More than 2 alcohols

① Attach suffixes like -diol, -triol to the end of the main chain's name.

② Assign lower numbers to provide at least one alcohol with a smaller number, and name them alphabetically.

③ Common names: The examples are as follows:

○ Ethylene glycol (ethane-1,2-diol)

○ Glycerol (propane-1,2,3-triol)

2. Physical Properties

⑴ Degree of alcohols

① Definition: The degree of carbon with an attached -OH group.

② Higher degree of alcohol → Lower solubility in water.

③ Increase in the degree of alcohol → Intermolecular forces are disrupted → Melting point and boiling point decrease.

○ Boiling points: 1-butanol (117 ℃) > 2-methyl-1-propanol (107 ℃) > 2-butanol (98 ℃) > 2-methyl-2-propanol (82 ℃)

○ Melting points: 1-butanol (-90 ℃) > 2-methyl-1-propanol (-108 ℃) > 2-butanol (-115 ℃)

○ Unlike boiling points, melting points are influenced not only by intermolecular forces but also by packing property, so the melting point of 2-methyl-2-propanol (25 ℃) is quite high.

⑵ Boiling points of alcohols

① Higher number of carbons leads to stronger intermolecular forces and higher boiling points.

○ Example: methanol (65 ℃) < ethanol (78 ℃) < propan-1-ol (97 ℃)

② Much higher boiling points than alkenes, alkynes, and alkyl halides.

③ 1,3-diols have higher boiling points than 1,2-diols.

○ Reason: 1,2-diols with well-formed intramolecular hydrogen bonding have weaker intermolecular hydrogen bonding.

⑶ Acidity of alcohols

① Acidity in solution: methyl alcohol > primary alcohol > secondary alcohol> tertiary alcohol

○ Key pKa values

○ Methanol (MeOH): 15.5

○ Ethanol (EtOH): 16

○ i-PrOH: 16.5

○ t-BuOH: 18

○ Solvation effect

○ Alcohols with more alkyl groups have weaker solvation effects due to hydrogen bonding.

○ As a result, alkoxide ions, which are the conjugate bases, are less stabilized, leading to lower acidity of alcohols with more alkyl groups.

○ Inductive effect

○ Inductive effects explain acidity in solution, but not in the gas phase.

② Acidity in the gas phase: methyl alcohol < primary alcohol < secondary alcohol < tertiary alcohol

○ No solvation effect in the gas phase.

○ The acidity of tertiary alcohols is the greatest because the alkyl groups have a strong effect on dispersing the negative charge.

○ Generally, the acidity of thiols is greater than that of alcohols due to the polarizability, that is, the size effect.

⑷ Strength of hydrogen bonding in alcohols

① Strength of hydrogen bonding: primary alcohol > secondary alcohol > tertiary alcohol

② Steric hindrance: primary alcohol < secondary alcohol < tertiary alcohol

3. Reactions

⑴ Overview

① Key aspect of reactions: Since OH- is a strong base and a poor leaving group, processes that transform hydroxy group into a good leaving group occur.

② Type 1: Dehydration reaction (Important to memorize): SN2 reactions involve primary or secondary alcohols. Non-SN2 reactions involve secondary or tertiary alcohols.

○ SOCl2 group: SN2 reaction

○ HCl group: SN1 reaction

○ POCl3 (catalyst: pyridine) group: E2 reaction

○ H2SO4 group: E1 reaction

③ Type 2: Alcohol protection and deprotection reactions

④ Type 3: Acid-base reactions

⑤ Type 4: Oxidation reactions

⑥ Type 5: Other reactions: Ether synthesis, ester synthesis, pinacol rearrangement reaction

⑵ 1-1. SN2 reaction

① Reagents: SOCl2, PBr3, PCl3, PCl5 + primary or secondary alcohols

○ Primary alcohols and secondary alcohols: Since X- is a weak base, SN2 reaction occurs rather than E2.

○ Reactivity: Secondary alcohols < Primary alcohols

○ Tertiary alcohols: SN1/E1 reactions are