Lab Report #10

H3C CH3 H3C NA C→XT Br Br₂ CH₂Cl₂ H3C Electrophilic addition of bromine, Br₂, to alkenes yields a 1,2-dibromoalkane. The reaction proceeds through a cyclic intermediate known as a bromonium ion. The reaction occurs in an anhydrous solvent such as CH₂Cl₂. CH3 Br In the second step of the reaction, bromide is the nucleophile and attacks at one of the carbons of the bromonium ion to yield the product. Due to steric clashes, the bromide ion always attacks the carbon from the opposite face of the bromonium ion so that a product with anti stereochemistry is formed. Draw curved arrows to show the movement of electrons in this step of the mechanism. Arrow-pushing Instructions Br CH3 H3C CH3

Consider this reaction: Br CH;OH Br-Br H3CO The mechanism proceeds through a first cationic intermediate, intermediate 1. Nucleophilic attack leads to intermediate 2, which goes on to form the final product. In cases that involve a negatively charged nucleophile, the attack of the nucleophile leads directly to the product. Br + CH3OH Br Intermediate 1 Intermediate 2 (product) In a similar fashion, draw intermediate 1 and intermediate 2 (final product) for the following reaction. OH + Br2 + HBr Br racemic mixture

There is great excess of H2O in this reaction.

The SN 1 mechanism starts with the rate-determining step which is the dissociation of the alkyl halide into a carbocation and a halide ion. The next step is the rapid reaction of the carbocation intermediate with the nucleophile; this step completes the nucleophilic substitution stage. The step that follows the nucleophilic substitution is a fast acid-base reaction. The nucleophile now acts as a base to remove the proton from the oxonium ion from the previous step, to give the observed product. Draw a curved arrow mechanism for the reaction, adding steps as necessary. Be sure to include all nonzero formal charges. Cl: Add/Remove step G Click and drag to start drawing a structure.

The SN 1 mechanism starts with the rate-determining step which is the dissociation of the alkyl halide into a carbocation and a halide ion. The next step is the rapid reaction of the carbocation intermediate with the nucleophile; this step completes the nucleophilic substitution stage. The step that follows the nucleophilic substitution is a fast acid-base reaction. The nucleophile now acts as a base to remove the proton from the oxonium ion from the previous step, to give the observed product. Draw a curved arrow mechanism for the reaction, adding steps as necessary. Be sure to include all nonzero formal charges. Br. Add/Remove step ك Click and drag to start drawing a structure.

methanol + CH3OH Suppose you were told that the above reaction was a substitution reaction but you were not told the mechanism. Evaluate the following categories to determine the reaction mechanism and then draw the structure of the major organic product. Type of alkyl halide: Type of nucleophile: Solvent: Is the product racemic?

196. Subject : - Chemistry

Draw the organic product you would expect to isolate from the nucleophilic substitution reaction between the molecules shown. Note: You do not need to draw any of the side products of the reaction, only the substitution product. SH + 0 Br + X S C Click and drag to start drawing a structure.

4. A CHEM 245 student wants to synthesize some ethylene glycol to use as antifreeze in his radiator this winter. He proposes the following reaction to his instructor, who quickly explains that this reaction won't work as proposed due to the student's choice of reagent. 1) NaH 2) H20 OH Но a) Why can't sodium hydride (NaH) be used as the nucleophile in the reaction above? b) Propose an alternate reagent that COULD be used with the ethylene oxide to successfully give the desired ethylene glycol product.

Substitution Reactions Predicting the product of a nucleophilic substitution reaction Draw the organic product you would expect to isolate from the nucleophilic substitution reaction between the molecules shown. Note: You do not need to draw any of the side products of the reaction, only the substitution product. HO + + Br xx X S C Click and drag to start drawing a structure.

The compound below is treated with chlorine in the presence of light. H3C CH3 H3C° `CH2CH3 Draw the structure for the organic radical species produced by reaction of the compound with a chlorine atom. Assume reaction occurs at the weakest C-H bond. • You do not have to consider stereochemistry. • You do not have to explicitly draw H atoms.

The following reaction is a/an example of H2 I H₂ ó H₂CCCC. H2 Addition Condensation Elimination Substitution Oxidation Cl H2 Cl₂and light H₂C-CH CC + HC CH3 CH3 H2 other + chlorinated products

Draw the structure of the organic product formed when the given compounds undergo the three-step reaction sequence indicated. Select Draw Rings More Erase C Br 1. NaOC,H5. C,H5OH 2. NaOH, H2O 3. H3O*, heat

Draw the organic product you would expect to isolate from the nucleophilic substitution reaction between the molecules shown. Note: You do not need to draw any of the side products of the reaction, only the substitution product. D xx + H₂O + X Click and drag to start drawing a structure.

For the given SN2 reaction, draw the organic and inorganic products of the reaction, and identify the nucleophile, substrate, and leaving group.

Classify each of the following organic reactions. Check all that apply for each organic reaction.

The compound below is treated with chlorine in the presence of light. H₂C CH3 H₂C CH3 Draw the structure for the organic radical species produced by reaction of the compound with a chlorine atom. Assume reaction occurs at the weakest C-H bond. You do not have to consider stereochemistry. • You do not have to explicitly draw H atoms. Undo

orgo chem questions

What reaction category/mechanism type does the following reaction fit? O addition substitution (SN1) substitution (SN2) O elimination (E1) O elimination (E2) HCI CI + HO

Draw reaction mechanisms for the following:

Draw the organic product you would expect to isolate from the nucleophilic substitution reaction between the molecules shown. Note: You do not need to draw any of the side products of the reaction, only the substitution product. OH- 0 + I X Click and drag to start drawing a structure.

What explains why many aldehydes and ketones can undergo self- condensation reactions in basic conditions? The alpha carbon can lose a proton and act like a nucleophile and the carbonyl carbon a an electrophile O The alpha carbon can gain a proton and act like an electrophile and the carbonyl carbon is a nucleophile O The oxygen of the carbonyl group can attack the carbon of the carbonyl group Only esters can undergo self-condensation reactions

12) Use the curved arrow formalism to show the movement of electron pairs in the following reaction and label each reactant as a nucleophile or an electrophile. CHÍNH CHỊCH, + CO Học Nha CH₂CH₂CI

What about the second step in the electrophilic addition of HCl to an alkene-the reaction of chloride ion with the carbocation intermediate? Is this step exergonic or endergonic? Does the transition state for this second step resemble the reactant (carbocation) or the product (alkyl chloride)? Make a rough diagram of what the transition state may look like?