Show what products you would expect from the following metathesis reactions, using the Schrock or Grubbs catalysts.
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Verified step by step guidance

1. Step 1: Identify the type of reaction. This is a metathesis reaction, which involves the exchange of alkene fragments between molecules, facilitated by a catalyst such as the Schrock or Grubbs catalyst.
2. Step 2: Analyze the structure of the starting material. The molecule contains two alkenes: one within the aromatic ring system fused with oxygen (benzopyran structure) and another in the side chain.
3. Step 3: Determine the role of the catalyst. The Grubbs or Schrock catalyst will break the double bonds in the alkenes and form new double bonds by exchanging alkene fragments.
4. Step 4: Predict the products. The reaction will likely result in the formation of a cyclic product due to the proximity of the two alkenes in the molecule. The catalyst facilitates the formation of a new C=C bond, leading to ring closure.
5. Step 5: Consider stereochemistry and regioselectivity. The metathesis reaction typically forms the most thermodynamically stable product, which in this case would be a cyclic compound with a new double bond. Ensure the product structure reflects the correct connectivity and stability.

Key Concepts

Metathesis Reactions

Metathesis reactions involve the exchange of partners between two alkenes, resulting in the formation of new alkenes. This process is facilitated by catalysts, such as the Schrock or Grubbs catalysts, which stabilize the transition state and lower the activation energy. Understanding the mechanism of metathesis is crucial for predicting the products formed from specific reactants.

Schrock and Grubbs Catalysts

Schrock and Grubbs catalysts are types of transition metal complexes used to promote metathesis reactions. Schrock catalysts are typically based on tungsten or molybdenum, while Grubbs catalysts are based on ruthenium. Each catalyst has unique properties that influence the reaction conditions and product distribution, making it important to choose the appropriate catalyst for specific substrates.

Product Prediction in Organic Reactions

Predicting the products of organic reactions, such as metathesis, requires an understanding of the structure and reactivity of the starting materials. In metathesis, the orientation and substitution patterns of the alkenes play a significant role in determining the final products. Analyzing the molecular structure and applying the principles of reaction mechanisms are essential for accurate product prediction.