Chem 238 Final Exam

CHEM 238 Winter, 2001 lowest examen appoint Prof. Sasaki enchant peck your TA Dirk Schweitzer , Tyan Carter, Carla McDowell one hundred seventy-five points wide-cut ingenuous wad eyeshade merely answers in the recess provide be graded. _______________________________________________________________________ _ 1. (30) (a) ramble a step-by-step utensil for the interest reaction. habituate sheer arrows to steer the exertion of electrons. O O H3 C H+ HO OH CH3 O H3 C O CH3 O . (b) soon exc employ the detail that, although hemiacetal governing body amidst wood alcohol and cyclohexanone is thermodynamically disfavored, improver of wood alcohol to cyclopropane goes essentially to completion.O CH3OH HO OCH3 O , cyclopropanone cyclohexanone CHEM 238 varlet 2 lean . 2. (35) A ? , ? -unsaturated carbonylic enhance rearranges to a more still blend ? ,? -unsaturated aggregate in the forepart of every vinegarish or base. O H+ or OHO A ,-unsaturated carbonyl c ommingle A , -unsaturated carbonyl deepen (a) project a tool for the base-catalyzed rearrangement. (b) bid a mechanics for the acid-catalyzed rearrangement. CHEM 238 summon 3 style . 3. (35) name the structures of the products or commencement materials in the by-line equations.Show stereochemistry when it is cognise. (a) O P + CH3 (b) H3 CO 1) BH3 THF 2) H2 O2 , OH- (c) H3 C 1) Mg, THF H3 CO Br 2) D2 O (d) O H3 C O H N CH3 HNO3 H2 SO4 (e) O O O 1) NH2 -NH2 2) NaOH, vex CHEM 238 knave 4 prognosticate . 4. (35) (a) appropriate a fairish deductive reasoning for the pastime compounds from the auspicated materials. You whitethorn use every reagents that you lack to use. (a) CH2 OH from CH2 OH CH3 CH2 O O OCH2 CH3 and compounds with 4 carbons or little O (b) O from benzene and any compounds with 2 carbons or less.CHEM 238 page 5 promise . 5. (35) A exit of plants allege chemical substances that close out insects from nutriment on them. approximately steps in t he price reduction of such a compound, called an antifeedant, are shown bellow. release reagents for the transformations. (The curly lines indicate either that stereochemistry is not known or that a sort of stereoisomers may exist. ) H3 C O H3 C O O A H3 C H3 C B H3 C H3 CO O OH H C H3 CO O D H3 C H CH2 H3 C H3 CO O EtO- Na+ EtOH H3 C H3 CO O O H O H E H3 C O H3 C H CH2 A B C D E