Worksheet for LA Review (2)

For the following Newman Projection, determine whether it is in the lowest energy conformation as drawn. Then, fill in the Newman Projection for the lowest energy conformation. You may use the table of A-values provided in the instructions to determine the correct answer. 2. H 3. CH3 (Me) Is this the lowest energy conformation? No For each number on the partially filled Newman Projection above, select the group that would make the lowest energy conformation. 1. CH2CH3 (Et) 4. H 5. CH(CH3)2 (i-prop) 5. 47 2 CH3 .3

Which compounds have torsional strain (also known as eclipsing strain) in their most stable conformation? Note that compound that has two rings has been drawn in its most stable conformation. Select more than one answer. Even the correct answer gets feedback on this one. Me Me Me Me Me Me D E A. Cyclohexane is a chair, which has only secondary carbons. Since cyclopropane is flat all of the adjacent C's are eclipsed, this giving rise to torsional strain. Since cyclopropane is flat all of the adjacent C's are eclipsed, this giving rise to torsional strain. DE

Please answer. Please be a hundred percent sure of your answer.

Perform a confirmational analysis on cyclohexane derivative 1. Draw out both possible confórmeles and circle the preferred (lowest energy) conformer. Using A, U or G values estimate the energy difference ( Change in G) between the two confórmeles and predict the approximate ratio of the two confórmers at room temperature.

Draw a structural formula of the RR and RS configuration of the compounds shown below.

C and D please!

Please confirm if my answer is correct or not. Due to the need for this to be correct I would like you to provide me with a confidence score in you answer on a scale from 1 to 10 how confident are you in your answer. Please be sure to double check your answer

Consider the structure of the molecule below The absolute configuration (R/S) of the chiral carbon with chlorine is The enantiomer of this structure is (draw it to the right): Draw a constitutional isomer of the molecule (draw it to the right):

Complete the question on paper and snap a photo and upload it as your submission in jpg or pdf format. CI IO H OH a. Generate a Newman projection of the molecule shown above. The red arrow indicated the direction from which your eyes are looking at the molecule. b. Also draw a Newman projection of a conformation that is less stable than the one that you have draw in a. There may be more than one correct option to generate a less stable Newman projection - you need only generate one. You can rotate around the C-C single bond to go between eclipsed and/or staggered conformations. c. Describe why the conformation in b. is less stable than a (name the interactions that make the conformation less stable). Point out where on your structure those interactions are (circling is fine).

Please answer questions 6, 7, and 8. They are all related to each other. Please write neatly, answer and label all parts, and circle answers.

Answer all the question below, please make sure to answer them all thoroughly.

For each molecule below, determine if it is an R or S configuration. Write the configuration below the compound.

CANNOT BE HAND DRAWN! Please help correct my work  Determine if your molecule contains any chiral carbons. If there are chiral carbons in your molecule, circle or highlight all of them.  If your molecule does not contain any chiral carbons explain why none of the carbons are chiral.

Please confirm if my answer is correct or not. Due to the need for this to be correct I would like you to provide me with a confidence score in you answer on a scale from 1 to 10 how confident are you in your answer. Please be sure to double check your answer

Draw a structural formula of the S configuration of the compound shown below. • Use the wedge /hash bond tools to indicate stereochemistry where it exists. Include H atoms at chiral centers only. • Ifa group is achiral, do not use wedged or hashed bonds on it. CH3 CH3 CH;CHCHCN CH,CH,CH,CHCH,CH, CH2NH2 Draw a structural formula of the RS configuration of the compound shown below. Use the wedge /hash bond tools to indicate stereochemistry where it exists. • Include H atoms at chiral centers only. If a group is achiral, do not use wedged or hashed bonds on it. ÇI

Q7-Fill in the boxes with the product(s) or starting material for the following reactions. Draw only the predominate regioisomer(s) and indicate the stereochemistry where appropriate. If a racemic mixture is formed, you may indicate this using a wavy line or mark the chiral center with an asterisk (*), and write racemic in the box. You may also draw both enantiomers and write RACEMIC in the box. NH₂ 1) LAH/THF 2) H₂O OH NH2 (S) (excess) NaOH/A H3O+/A H₂N OH Ph A + H₂O* H₂/Pt NH2 COOH 1) LAH/THF 2) H₂O SOCI₂ -CN 1) NaOH/A 2) Etl OEt 1) PhMgBr (excess) 2) H₂SO, (conc.)/A 1) DIBALH, -78°C 2) H₂O* 4 .COOH

8. Consider 1-bromo-2-methylpropane. Draw a Newman projection of the following (when viewed directlyalong the C1-C2 bond) a. staggered conformation of lowest energyb. eclipsed conformation of highest energy

5. Draw the structure of (S)-1-bromo-1-chloropropane. Take care to indicate the three- dimensional stereochemistry properly. 6. How many chiral centers does the following compound contain? CH3 7. Label each chiral carbon in the molecule below as having R or S configuration. HO₂C H F. H3C H CH₂CH3

1a. How many stereogenic centers are present 1c. Draw a three-dimensional structure of a in the structure below? Indicate them with asterisk(s). How many stereoisomers stereoisomers are possible? chiral compound with the molecular formula of C4H4Cl₂ that does not have a stereogenic carbon. In addition, draw the enantiomer of this compound. Number of stereogenic centers: Number of stereoisomers possible: 1b. Draw one of the two most stable stereoisomers of the compound in 1a using a planar structure with wedges and dashes. Now draw it in its preferred chair conformation. 1d. Draw two meso compounds with the molecular formula of C7H14.

Please do it all neat and clean correctly... If you can't do it all then please don't touch it. Thank you

F) Circle the letter corresponding to the relationship of each pair of structures: Identical (I), Conformers (C), Enantiomers (E) (enantiomers can have different conformations). FIRST... determine the absolute configuration of chiral centers. H. ІН' I H | H с H Me E Me