What is the major final product of the following reaction sequence? Only ane enantiomer of the possible products is shown. Br 1) H=K, NaH, THF 2) Na, NH3 (liq), t-BUOH 3) Cl2, CH,Cl, CI CI CI H CI H CI H CI
Reactive Intermediates
In chemistry, reactive intermediates are termed as short-lived, highly reactive atoms with high energy. They rapidly transform into stable particles during a chemical reaction. In specific cases, by means of matrix isolation and at low-temperature reactive intermediates can be isolated.
Hydride Shift
A hydride shift is a rearrangement of a hydrogen atom in a carbocation that occurs to make the molecule more stable. In organic chemistry, rearrangement of the carbocation is very easily seen. This rearrangement can be because of the movement of a carbocation to attain stability in the compound. Such structural reorganization movement is called a shift within molecules. After the shifting of carbocation over the different carbon then they form structural isomers of the previous existing molecule.
Vinylic Carbocation
A carbocation where the positive charge is on the alkene carbon is known as the vinyl carbocation or vinyl cation. The empirical formula for vinyl cation is C2H3+. In the vinyl carbocation, the positive charge is on the carbon atom with the double bond therefore it is sp hybridized. It is known to be a part of various reactions, for example, electrophilic addition of alkynes and solvolysis as well. It plays the role of a reactive intermediate in these reactions.
Cycloheptatrienyl Cation
It is an aromatic carbocation having a general formula, [C7 H7]+. It is also known as the aromatic tropylium ion. Its name is derived from the molecule tropine, which is a seven membered carbon atom ring. Cycloheptatriene or tropylidene was first synthesized from tropine.
Stability of Vinyl Carbocation
Carbocations are positively charged carbon atoms. It is also known as a carbonium ion.
This question is from an O-chem study guide
If you can please go through the reaction steps and help me understand why it has the steriochemistry that it does?
![**Title: Reaction Sequence and Stereochemistry**
**Question:**
What is the major final product of the following reaction sequence? Only one enantiomer of the possible products is shown.
**Reaction Sequence:**
1. Starting material: Benzyl bromide
2. Reagents and conditions:
- 1) Sodium hydride (NaH), Tetrahydrofuran (THF)
- 2) Sodium, Ammonia (liquid), tert-Butyl alcohol (t-BuOH)
- 3) Chlorine (Cl₂), Dichloromethane (CH₂Cl₂)
**Structures of Possible Products:**
1. **First Structure:**
- Benzene ring attached to a 3-chloropropene with the double bond in trans configuration.
- Hydrogen atom at the first carbon of the propene chain.
2. **Second Structure:**
- Benzene ring attached to a 3,3-dichloropropene.
- Both chlorine atoms attached at the same carbon.
3. **Third Structure:**
- Benzene ring attached to a saturated propyl chain with one chlorine substituent on each of the first two carbons.
- The chlorine on the first carbon is on the opposite side (wedge) to the hydrogen on the second carbon (dash).
4. **Fourth Structure:**
- Similar to the third structure, but both hydrogen atoms are on one side (wedge) and chlorine atoms on the opposite side (dash).
**Explanation of Process:**
- **Step 1** involves deprotonation of the alkyne followed by nucleophilic substitution to form the propargylic intermediate.
- **Step 2** likely involves anti addition, transforming the alkyne to a trans-alkene or adjusting the stereochemistry.
- **Step 3** introduces chlorine atoms. The process indicates a preference for anti-addition, where chlorines add across the double bond.
**Diagrams Interpretation:**
These structures illustrate possible outcomes based on the orientation (cis/trans) and stereochemistry (enantiomers) of chlorine addition. Understanding these will help predict the most stable configuration leading to the major product shown.](/v2/_next/image?url=https%3A%2F%2Fcontent.bartleby.com%2Fqna-images%2Fquestion%2F44c34136-e117-491b-b58f-d0d94a4d60dd%2F33142463-cac1-4240-ab77-64a1776aad9e%2Fdfff808_processed.jpeg&w=3840&q=75)
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