Homework answers / question archive / CHEM 122: Introduction to Organic Chemistry Spring 2021 Quiz 4, May 7 Name_________________________ 1) (8 pts) Determine if each of the following compounds is chiral or achiral

CHEM 122: Introduction to Organic Chemistry Spring 2021 Quiz 4, May 7 Name_________________________ 1) (8 pts) Determine if each of the following compounds is chiral or achiral

Sociology

Share With

CHEM 122: Introduction to Organic Chemistry Spring 2021 Quiz 4, May 7 Name_________________________ 1) (8 pts) Determine if each of the following compounds is chiral or achiral. If chiral, draw the enantiomer and name the original compound according to IUPAC nomenclature, using appropriate R/S designation to show handedness. H SH H H3C OCH3 H 2) (4 pts) Which of these three compounds has the highest boiling point? Which is least likely to be soluble in water? Which will react with NaOH? Briefly explain your reasoning. OH SH O 3) (5 pts) Predict the product of each of the following reactions. HO OH OH K2Cr2O7 H2SO4 PBr3 4) (5 pts) a) Predict the major product obtained in the following reaction: OH conc. H2SO4 heat b) Write out the 3-step arrow pushing mechanism leading up to this product. 5) (8 pts) a) What two alcohols could give the following alkene upon treatment with concentrated sulfuric acid? conc. H2SO4 heat b) Which alcohol would be the better choice to make this alkene? Explain, considering what other products are formed in each reaction, and the favored product in each case. CHEM 122: Introduction to Organic Chemistry Homework 4 (Thursday May 6): Chapter 5: Alcohols, Ethers, and Thiols. (15 problems) Chapter 6: Chirality: The Handedness of Molecules. (8 problems) Chapter 5: 1. Explain in terms of noncovalent interactions (intermolecular forces) why the lowmolecular-weight alcohols are more soluble in water than the low-molecular-weight ethers. 2. Show hydrogen bonding between the oxygen of diethyl ether and a hydrogen of water. 3. From each pair, select the compound that is more soluble in water. a) CH3OH or CH3OCH3 OH b) CH3CHCH3 CH2 or c) CH3CH2CH2SH CH3CCH3 or CH3CH2CH2OH 4. Give the structural formula of an alkene or alkenes from which each alcohol can be prepared. a) 2-Butanol b) 1-Methylcyclohexanol c) 3-Hexanol d) 2-Methyl-2-pentanol e) Cyclopentanol 5. Write equations for the reaction of 2-butanol with these reagents. a) H2SO4, heat b) K2Cr2O7, H2SO4 6. Show how to convert cyclohexanol to these compounds. a) Cyclohexene b) Cyclohexane c) Cyclohexanone d) Bromocyclohexane 7. Show reagents and experimental conditions to synthesize each compound from 1propanol. Br Br Br (e) (d) OH (b) (f) O (c) (a) OH (g) OH O (i) (h) O H 8. Write the common name for each ether. O a) b) [CH3(CH2)4]2O c) CH3CHOCHCH3 9. Write the IUPAC name of each thiol. SH a) CH3CH2CHCH3 b) CH3CH2CH2CH2SH c) 10. Write the common name for each thiol in Problem 9. 11. Explain why methanethiol, CH3SH, has a lower boiling point (6oC) than methanol, CH3OH (65oC), even though methanethiol has a higher molecular weight. 12. Draw structural formulas and write common names for the six isomeric ethers with the molecular formula C5H12O. 13. Show how to prepare each compound from 2-methylcyclohexanol. O CH3 a) b) CH3 d) CH3 OH CH3 c) 14. The mechanism of the acid-catalyzed dehydration of an alcohol to an alkene is the reverse of the acid-catalyzed hydration of an alkene. The dehydration mechanism occurs by the following three steps: Step 1: Add a proton. Step 2: Break a bond to form stable molecules or ion. Step 3: Take away a proton. These three steps are illustrated here by the dehydration of 2-butanol to give 2-butene. Use curved arrows to show the flow of electrons in each step; that is, show how each bond-making or bond-breaking step occurs. OH Step 1: H+ H O H H O H Step 2: + H2O Step 3: and H + H+ 15. Use the reactions we learned in Chapter 3 and this chapter to show how to bring about the following chemical transformations. Some transformations will require only one step. Others will require two or more steps. OH a) HO b) O c) OH Br d) O CH2OH OH e) CH3 f) OH Chapter 6: 1. Which of the following objects are chiral (assume that there is no label or other identifying mark)? a) Pair of scissors b) Tennis ball c) Paper clip d) Beaker e) The swirl created in water as it drains out of a sink or bathtub. 2. 2-Pentanol is chiral, but 3-pentanol is not. Explain. 3. 2-Butene exists as a pair of cis-trans isomers. Is cis-2-butene chiral? Is trans-2-butene chiral? Explain. 4. Which of the following compounds contain stereocenters? a) 2-Chloropentane b) 3-Chloropentane c) 3-Chloro-1-butene d) 1,2-Dichloropropane 5. Which of the following compounds contain stereocenters? a) Cyclopentanol b) 1-Chloro-2-propanol c) 2-Methylcyclopentanol d) 1-Phenyl-1-propanol 6. Draw the mirror image for each molecule: COOH H H2 N C H CH3 a) OH b) CH 2 OH O OH H H OH H HO H H OH c) H3 C NH2 d) 7. Mark each stereocenter in these molecules with an asterisk. Note that not all contain stereocenters. OH CH3 O N CH3 a) OH b) O O OH c) NH 2 d) 8. Which of the eight alcohols with a molecular formula of C 5H12O are chiral?