Question

OCH3 3. Indicate the electrophilic or nucleophilic centers for the following compounds: a) b) d) 4. Answer the following questions regarding 2,3-dimethylbutane: a) draw any staggered Newman projection of this compound looking down the C2-C3 bond. b) draw the highest energy conformation (as a Newman projection). Label each example of steric and/or torsional strain. c) draw the lowest energy conformation. Identify any sources of steric or torsional strain if present. m md iminetahm 5 Draw tra possiblechair conformatex For Jbrom-s-7ethiTmethychayo and mdicate f one with the lowest energy. A lower than the barrier to rotation for bond B? 6. Why is the barrier to rotation for bond bond B bond A

Answer 1

As atta clad to Electroplilic centre ORygen and as p2-ybaidizatior Nucleofluilic ceritre Move electronegathve +han carton Electopailic cente Dinuctly attached to oxygen atem (more electronegate Nu deo plailic cettre Nucdeopeu'lic cete Ele ctro kelic Cethe

Electroplitic cente →Nudeo人lilc centhe im ethylbutone 2 3-D eH CH3 3/ Point of vieus CH-C-C CH3 Front canbos Back cas bom circle) Denoted by clot) Denoted CH3 H HC cM3 codinma tion In Staggored gronfs eclipsed oum in mot are eclipredl High energy c inmation Beulky geoups eelipsedh Cofiaumation cH3 ane n Stenic strain Stevic train ell as Cas un gle 6traim is maximum

Low eergy cofinmatron buthy groups anti al anti do are each othes Fhere s lers Steric strain but onglo train Hhere CH3 cMs Stesic tinolarance Couse Atiain a tuimy geoups are H C hear 5. -RLomo -cis -ctyl4-msthy yelotexa CH CH3 cis at 1,3 position mans aNRial-axial 3 eguatorial egaatova I,2 aud ,y-us maans Caxralegua alax OY 1axial bond Ri-axial both 1-5 equatoial bond -CHCH and-cH eguatov'al are ne H H B-eguatral cn CHS -cu both are レH axi'al (4ae strain CM CN 3 CHS ,のっっっうっっ00のの の00000のs

A 6 . Doubta bend in cisoidl celirmathon CMore stable) Doubla intranoid Lotirmation Len staba So bend as luigher eargy barsier tean clue to cisoid conrna achen