ORGANIC - CLUTCH CH ALCOHOLS, ETHERS, EPOXIDES AND THIOLS

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2 CONCEPT: ALCOHOL NOMENCLATURE Glycols: Alcohols with two hydroxyls are called ; with three hydroxyls are called Always give most priority to the OH group. EXAMPLE: Provide the correct common and IUPAC name of the following alcohols. a. b. Page 2

3 CONCEPT: ETHER NOMENCLATURE Common Name: List alkyl groups in alphabetical order and follow with the word IUPAC: Smaller half of the ether is named as an substituent on the main alkane chain EXAMPLE: Provide the correct common and IUPAC name of the following ether Page 3

4 CONCEPT: EPOXIDE NOMENCLATURE Cyclic ethers are named as a unique functional group due to increased reactivity. 3-membered ethers are called or Cycloalkane Convention: Name the ring as a cycloalkane, adding the prefix and location if necessary Epoxy Convention: Name as a di-located substituent on the longest carbon chain Oxide Convention: Name as an alkene, followed by the word Page 4

5 PRACTICE: Provide ALL the names applicable for the following molecule Page 5

6 PRACTICE: Provide ALL the names applicable for the following molecule Page 6

7 CONCEPT: SULFUR NOMENCLATURE Sulfur is similar to oxygen in its atomic composition, so it forms oxygen compound analogs. Alcohol has higher priority than thiols EXAMPLE: Provide the IUPAC names (and common names if appropriate) for the following compounds. a. b. Page 7

8 CONCEPT: SYNTHESIS OF ALCOHOLS OVERVIEW There are 4 different techniques commonly used to create alcohols in Organic 1. Thankfully, you already know all of them! Page 8

9 CONCEPT: CONVERSION OF ALCOHOLS TO GOOD LEAVING GROUPS Alcohols are terrible leaving groups. If we want to react with them, they need to be transformed. They can be converted into or 2 o and 3 o Alcohols with HX: SN1 mechanism 1 o alcohols with HX: SN2 mechanism Page 9

10 CONCEPT: CONVERSION OF ALCOHOLS TO GOOD LEAVING GROUPS SOCl2 and PBr3 are two of the most commonly used reagents to transform alcohols into alkyl halides They always proceed with of configuration. 1 o and 2 o Alcohols to RX: SN2 mechanism EXAMPLE: Determine the mechanism for the following reaction. Draw the final product. Page 10

11 CONCEPT: CONVERSION OF ALCOHOLS TO GOOD LEAVING GROUPS Alcohols can attack sulfonyl chlorides to create sulfonate esters. They always proceed with of configuration. Alcohols to Sulfonate Esters: Page 11

12 Alcohol Conversion Summary: Page 12

13 CONCEPT: SYNTHESIS OF ETHERS 1. Williamson Ether Synthesis (SN2 of 1 o or 0 o RX) Substitution with an oxide base. 2 o and 3 o alkyl halides will favor Page 13

14 CONCEPT: SYNTHESIS OF ETHERS 3. Alkoxymercuration of alkenes Same mechanism as oxymercuration, but using as the nucleophile instead of H2O. Page 14

15 2. Acid-Catalyzed Alcohol Condensation Only forms ethers. Page 15

16 4. Acid-Catalyzed Alkoxyation Same mechanism as acid-catalyzed hydration, but using as the nucleophile instead of H2O Page 16

17 PRACTICE: Predict the product for the following reaction PRACTICE: Predict the product for the following reaction Page 17

18 CONCEPT: CLEAVAGE OF ETHERS Ethers are very combustible, but unreactive. They contain two strong C O bonds that are not easy to break. They only undergo one synthetically useful reaction: cleavage in the presence of strong acid. Mechanism: EXAMPLE: Predict the product of the following reaction Page 18

19 CONCEPT: TERT-BUTYL ETHER PROTECTING GROUPS Protecting groups are used to shield reactive moieties while reactions are happening on other parts of the molecule. By definition, they must be completely reversible. EXAMPLE: Will the following reaction proceed efficiently as drawn? Why or why not? Page 19

20 t-butyl Ether: Addition of isobutylene through reversible acid-catalyzed alkoxylation Page 20

21 CONCEPT: SILYL ETHER PROTECTING GROUPS A group used to protect alcohols are silyl (silicon) chlorides. Mechanism: TBDMS is the most common silyl chloride in Organic Chemistry 1 EXAMPLE: Predict the product of the following reaction Page 21

22 CONCEPT: SHARPLESS ASYMMETRIC EPOXIDATION Enantioselective reactions are ones that generate enantiomer in significantly higher yield than another. Converts allyl alcohols into enantioselective epoxides depending on the tartrate used (+) or (-). General Reaction: Always draw alcohol on the corner of the double bond. Then determine chirality using DET. Page 22

23 CONCEPT: REACTIONS OF THIOLS Thiols contain an hydrogen, so they become excellent nucleophiles after exposed to These nucleophiles are called Sulfide Synthesis: Disulfide Synthesis: Page 23

24 CONCEPT: OXIDATION OF SULFIDES Oxidation reactions involve an increase in the content of a molecule Sulfides are more reactive than ethers because it has an expanded octet and can form additional bonds with other atoms. They are particularly susceptible to oxidation. Page 24