Chem 210 Exam II with complete solutions already graded A+

electrophiles electron seeking reagents that have room to accept a electron pair nucleophiles reagents seeking a nucleus to which to donate a pair of electrons proton transfer or protonation reaction the transfer of a proton from one base to another transition state lying between the products and reactants free energy of activation (delta G double dagger) the height of the barrier, the energy that the reactants attain in reaching the the transition state electrophilic reactions lewis acid and base, strong acid-2 steps, weak acid- 3 step electrophilic reaction strong acid 1)protonate 2) capture C+ regioselectivity more stable of the C+ forms faster C+ stability 1) resonance 2) 3degree> 2degree>1degree( how many c's bonded to electrophilic reaction weak acid 1)protonate pi bond w/ actual acid 2)capture C+ 3)deprotonate conformations different arrangements in space of the atoms of a molecule due to rotations around single bonds,energy differences dictated by noncovalent interactions garche 60 degree in newman projection anti 120 degree in newman projection conformers same connectivities but differ in spatial positions of atoms in relations to eachother naming alcohols change the ending e to ol, for two diol stereoisomers same connectivity and differ in the their atoms are oriented in space, same formula, same connectivity, different fixed geometry configurational isomer differ in the arrangement of their atoms in space and cannot be converted from one into another by rotations about single bonds enantiomers stereoisomers that are mirror images of one another, that are not superimposable diastereomers Stereoisomers that are not mirror images of each other. aka not enantiomers optically active chiral, optically inactive achiral chiral anything that cannot be superimposed on to its mirror image achiral anything that can be superimposed on to its mirror image stereocenter a tetrahedral atom that is bonded to four different substituents racemic mixture contains equal concentrations of 2 enantiomers and showes no optical rotation absolute configuration the actual orientation in space of the groups around a stereocenter trans 2 substituents may be on opposite sides of the plane of a ring cis 2 substituents may be on same sides of the plane of a ring resolution of a racemic mixture the separation of a mixture of enantiomers resolving agent the reagent used in the process of resolution of a racemic mixture complexation/decomplexation reaction nde+open shell <=> sigma substitution reaction sigma<=> sigma a) bronsted base b) at unhindered, sp3 C addition reaction pi->2 sigma elimination reaction 2sigma-> pi rate determining step highest absolute E transition step regioselectivity of rxn the ration of products if both carbon bond and reagent are unsymmetrical then 2 outcomes possible actual acid H-A+H2O->H30(+)A(-) eclipsing an atom siting right in front of another(newman) dehedreal angle front to back (newman) energies of interaction e-/e- replusion charge/charge(partial/partial) h-bond donor/ accpter steric/size hinderence e-/e- replusion all staggered form is better than eclipsed unless there is evidence, steric size hinderence repulsion of attached groups abuses bending charge/charge(partial/partial) attractive/ replusive h-bond donor/ accepter attractive hydrogen bonding small ring conformations 3-6 atoms cyclobutane bends butterfly up and down cyclohexane bend one end up, one end down axial sites straight up or down from hexane ring equatorial sites angle out parallel to c-c bond to sites away more stable in ring larger groups in equatorial sites isomerism different molecules, same formula, different connectivity=structural/ constitutional isomers chirality any system that creates handedness, create two and only two objects that have non-identical mirror image case 1 stereoisomer double bonds with different pairs of groups on each end create two and only two stereoisomers, both achiral (E and Z) case 2 stereoisomer oppositely substituted even- sized rings 2 and only 2 stereoisomers, achiral (can't name, describe with cis and trans) case 3 stereoisomer tetrahedral stereocenter 2 and only 2 stereoisomers, both chiral(R and S) 1 stereocenter 2 stereoisomers (R,S) both chiral, enantiomers(R,S) 2 dissimilar stereocenter create 4 stereoisomer, all chiral 2 similar stereocenter 3 stereoisomers, 2 chiral(SS&RR)