CHEM 2030 1st EditionExam # 2 Study GuideOverview:Chapter 3Reactions of Alkenes and Alkynes-Last section of the chapter Chapter 4Aromatic CompoundsElectrophilic Aromatic SubstitutionChapter 5Stereoisomers-Until Slide 18Chapter 3: Alkenes and AlyknesKey Terms and Sequences you need to know:Hydroboration (of Alkenes)Addition of H-BB = electrophileBond breaking and making occur in 1 stepEx on slide: Propene and Borane  Tri-n-propylborane3(CH3CH=CH2)3 + BH3  CH3CH2CH2CH2 – B – (CH2CH2CH3)2Now we can make them alcohols: Final Product when we add 3H2O2 + 3 NaOH  N-Propyl alcohol, Sodium Borate, and Water*Be familiar with other alcohol synthesis as wellHydrogenation of Alkenes: Use H2 as a catalyst to make a radical reaction! Heterogeneous Reactions: (C=C + H2) aka cis-alkenes The complete hydrogenation all the way to alkene is easy. The key is to stop at the stage of the alkeneOzonolysis: Add an O to both sides of the C=COzone = 03*Might ask you to find the 2 products of OzonolysisEx: 1-Butene CH2=CHCH32 Products: H2C=O and O=CH-CH3If you add H2 to Pentyne = 2 PenteneIf you add H2 again = PentaneThis is a heterogeneous hydration reactionCompare and Contrast their RegiochemistryConsider the Markovnikov ProductThe book uses the addition of H-Cl to propene as an example (pg. 84)We either add the H+ to C-1 making it an Isopropyl cation or adding it to C-2 making it a propyl cationConclusion: The proton adds to C-1 to form only the isopropyl cation. Why? Consider the carbocations to be classified in 3 separate groups to determine how many R groups are attached to the positively charged atom:1. Primary (1 R group)2. Secondary (2 R groups)3. Tertiary (3 R groups)The higher the R group, the more stableTertiary > Secondary > Primary > Methyl (unique)Acid-Cat Hydration of Alkenes (From Ch 1. But might see it still)Be able to make a line segment structure of the substrate and product and reaction of Cyclopentene with Hydrogeniodid (HI). Include the IUPAC name too:Cyclopentene= 5 C’s, 1 double bond +HI  5 C’s, all single bonds, I branched outwhere the double bond was in the reactant = Iodo-cyclo-pentaneBe able to make an abbreviated structure drawing of products:Ex: 1-Methylcyclopentene + (HI) Hydrogeniodid5 C, H2 connected to all but H3 is connected to one+ (HI)  2 options can be formedThe one that has the CH3 and I connected to the C is the Markonikov Product!Addition to Conjugated Dienes:1,2 Addition (1st and 2nd carbons)1,4 Addition (1st and 4th carbons)*Remember that when counting carbons you can start from either the left of the rightAllylic Cation: A C=C is adjacent to +cationA Cyclic Product: 3 Pi bonds  2 Sigma and 1 Pi BondOxidation of Alkenes to Diolis:Break on Pi-bond of DBAttach –OH to both alkene-CGlycols: Compounds with 2 hydroxyl groups on adjacent carbonsChapter 4: Aromatic CompoundsElectrophilic Aromatic SubstitutionDirecting EffectsResonance Forms of Sigma ComplexesBenzene = C6H6Parent Hydrocarbon for aromatic compoundsStable properties, highly unsaturated, isometric structuresPlanar; C-C bond = 1.39AOrbital Model: SP2 hybridized2 Symbols: Kekule (Helps with valence electrons; We use this) or Delocalized Pi Cloud (more accurate and shows equally distributed electrons around the ring).Benzene Reacts with Substitutions:Fe2/Br2 are the examples in the bookCatalyst = Lewis AcidFeCl3 or FeBr3…. Depending on what benzene is reacting withFinal Product: One of the Fe or Br leaves the other single bond and connects to the larger molecule, making the single Br+ (positive) and the Fe- with the 4 attachments (negative)Include dots and arrowsResonance Model for Benzene:The double bonds shift positions and are interchangeable but it is the same moleculeStabilization/Resonance Energy: Actual energy, what most stable contributing structure*Real Benzene is more stable, and heat is much lower than expectedCyclohexene = 28.6 kcal/mol (+H-H)Basically, add 28.6 kcal for every double bond in the structureResonance: All atoms occupy the same positions in both structuresKekule Structure: 6 C located on the corner of the hexagon, 1 H attached to every CReactions are so fast, typical reactions aren’t possible for alkenesC valence = 4Single and double bonds alternate around ringsNomencalature of Aromic Compounds:**Memorize theseBenzene: C6H6Toluene: CH3Styrine: CH=CH2Phenol: OHAnisol: OCH3Benzaldehyde: CH=OAcetophenone: CH3C=OBenzoic Acid: CO2HAniline: NH2Cumene: CH3CHCH3Benzenes:Bromo: Br-Chloro: ClNitro: NO2Ethyl: CH2CH3Propyl: CH2CH2CH3When more than 2 substuents are present, positions are determined by the number in the ringOrtho: (2,6)Meta: (3,5)Para: 4X: 1 (Attached to the Ipso-carbon)Different Substitution Methods w/ Sigma Complexes: (Pg. 123)Nitration: NO2+ Ex: Nitrobenzene (Pg. 126)Sulfination: SO3 (Pg. 126)Chlorination: Cl (3 part sigma complex)Sp3 Hybridized, It is bonded to 4 other atoms with no double bondsFriedel-Crafts Reaction:The alylation or acylation of an aromatic compound2 Types:1. R+: Hard to stop at monoalkylation, doesn’t work with all kinds of alkyl halide, alkyl might rearrange; Reversible2. RCO+ = The “good” FC reaction, Easy to stop at monoacylation stage; Not reversibleSubstituent Effects in Electrophilic Aromatic Substitutions:O/P-Directors Stabilize Ipso Charge: Lone pairs at ipso-attached atom (Benzine Ring)Alkyl groupsCan be activating/deactivating CH groups includingM-Directors Destabilize Ipso Charge: Positively charged ipso-attached atomAlways deactivatingPull electron density (O) away from carbon ©-Aka it always has a double bond O-Exception: CyanoNitration of Toulene: (CH3) Rotate where the charge + is (1,3,5) unless Meta (2,4,6)CH3 at the top, NO2 (H) 1,4 = Ortho, Para(H) = 3 = MetaChapter 5: Stereoisomers, Chirality and Geometrical Isomers(Only go to slide 18)Stereoisomers: Same number and order of atoms, but different arrangements of the atoms in spaceChiral: Property of handiness, look in a mirrorAchiral: A circle, same even if it’s in a mirrorEnantiomers: NonsuperimposedSame as archival properties (mp, bp, density, and spectra)Different Chiral Properties:Direction in plane polarized light (# of degree’s)Different in biological settingsDifferent in sign of rotationStereogenetic Carbon Atom: 4 Groups attached to it = Stereogenetic CenterGives rise to stereoisomersConfiguration: Arrangement of the 4 groups attached to the Stereogenetic CenterA,B,C,D: By priority rules1. Atomic Number, the larger, the higher the