Chemistry 140C Midterm-1 Version 1 Winter 2011 Your Name (Please Print) _______________Key____________________________ Your Student ID# ________________________________________________ Wednesday January 26, 2011 11:00 am-‐ 12pm Mark your final answer clearly please! Additional blank pages are at the end if you need them. Please indicate if the final answer will be found at the end of the exam! Good Luck! ) Question 3: What is the major product in the following reaction? Why? One sentence maximum. Please CIRCLE your answer.) Question 1: What is the product of the following reaction? (5 pts. or .Name: ID# Signature: (5 pts.) Question 2: What is the product of the following reaction? (10 pts. the labeled oxygen will be in the product.) Devise an isotope-labeling experiment that might distinguish your two mechanisms. Addition-‐Elimination O O H OH HO OH HO + H O H O HO OH HO OH + H O O O O O HO OH2 H Cl- . If the reaction goes through the addition elimination mechanism. (Hint:Consider the possible sites of protonation in the molecule and the mechanistic consequences of each. the two mechanisms are easily distinguished. whereas the carbocation (SN1) type pathway will result in product free of isotopically labeled oxygen. HCl.Name: ID# Signature: (35pts.)Question 4: Propose two possible mechanisms for the following reaction. Δ If the starting material is isotopically labeled at the alcohol oxygen atom. Name: Carbocationic Pathway ID# Signature: O OH HO H+ O OH2 HO O O H ClHO O O O . Name: ID# Signature: (25 pts.)Question 5: Draw a step-by-step mechanism for the following transformation: N O N O H+ N OH N H+ O H H N O H N H OH O H O . Name: O N N O ID# Signature: N H OCH2CH3 O OCH2CH3 H O N N O N O H H2O N H H O H N H O H H2O O . Name: ID# Signature: (20 pts.) Question 6: Draw a step-by-step mechanism for the following transformation: HO O OH H+ HO H O OH O OH OH H O H OH OH H+ O O H O O .