Organic Chemistry P 267

Hydrocarbon Hydro: hydrogen Carbon Additional element: Nitrogen, Oxygen, Sulphur Atomic number of carbon = 6 Valence electrons of carbon = 4 Each carbon atom has 4 bond in compound Ex: alkanes Alkanes: hydrocarbon that consist of hydrogen and carbon, (single bond)

CH4, methane C2H6, ethane C3H8, propane C4H10, butane C5H12, pentane

C6H14, hexane C7H16, heptane C8H18, octane C9H20, nonane C10H22, decane

Structure Types of Propane Stick and ball model Displayed Formula 3 dimensional Formula H H Structural Formula H H CH3CH2CH3 H H H H Molecular Formula Skeletal Formula C3H8

ALCOHOL (-OH) PROPANE PROPANOL

ALCANOIC ACID BUTANOIC ACID BUTANE

ALDEHID/ALCANAL PENTANAL PENTANE

Ketones Butan-2-one

Alkylamine R-NH2 CH3CH2CH2NH2 Propylamine

ESTHER (Alkyl Alkanoate) propanoate methyl

2- Methyl Hexane Hydrocarbon with Branch 6 5 4 3 2 1 -Find the longest carbon chain, give the name - Find branch and give the name to the Branch: Carbon:Alkyl; 1 C atom: methyl 2 C atom: ethyl 3 C atom: propyl Halogen: F(Floro), Cl(Chloro), Br(Bromo), I(Iodo) - Give the number, branch number is the smallest number Same branch: 2 branchs: di 3 branchs: tri 4 branchs: tetra 2- Methyl Hexane

the branches names arranged alphabetically 3-bromo 9-chloro 4-methyldecan-3-ol

6-chloro 4-ethyl octan-3-one

Alcanal, and alcanoic numbering begin from C attached to the function 5 4 3 2 1 4- methyl Pentanal

4,6 -diethyl 2,4,7 -trimethyl nonane Same branch: 2 branchs: di 1 2 3 4 6 5 7 8 9 Same branch: 2 branchs: di 3 branchs: tri 4 branchs: tetra 4,6 -diethyl 2,4,7 -trimethyl nonane

Alcanal, and alcanoic numbering begin from C attached to the function 6-ethyl 3-floro 4,7-dimethyl octanoic acid Remember that the branches names arranged alphabetically

Task Copy the table 15.2 page 270 in to your book

Determination of element mass in compound Compound: AmBn Mass of element A = Mass of element B = Find mass of carbon in 88 gr CO2 Mass of carbon = = = 24 gr

Determination of empirical formulae of organic compound 100,00 g amino acid(CpHqOrNs) react with oxygen and produced 117,10 g of carbon dioxide and 59,92 g of water. In kjeldahl a second of amino acid produced 22,64 g ammonia, determine the empirical formula of amino acid Answer - write the information mass of amino acid = 100 gr mass of carbon dioxide (CO2) = 117,10 gr mass of water(H2O)= 59,92 g mass of ammonia (NH3) = 22,64

Find mass of carbon in carbon dioxide = 31,94 g Find mass of hydrogen in water = 6,66 g Find mass of nitrogen in ammonia = 18,64 g Find mass of oxygen in amino acid =mass of amino acid – carbon mass – hydrogen mass - nitrogen mass = 100 – 31,94 – 6,66 – 18,64 = 42,76 gr

C2H5O2N Compare mass of the elements C : H : O : N 31,94 : 6,66 : 42,7 : 18,64 Compare mol of the elements 31,94/12 : 6,66/1 : 42,76/16 : 18,64/14 2,67 : 6,66 : 2,67 : 1,33 Divide by the smallest mole 2 : 5 : 2 : 1 Determine the empirical formula C2H5O2N

Reactions Subtitution C H Br + OH  Br- OH-

Addition Double bondsingle bond Triple bonddouble or single bond Elimination single bondDouble bond double Triple bond C H + H2O OH  OH C H  H2O +

Hydrolysis Reaction involve breaking covalent bonds by reaction with water + OH  HBr H2O

Breaking Bonds in Different Ways Homolytic fission Each atom break to free radical (atom with unpaired electron  + Heterolytic fission Each atom break to ion (cation and anion) - +  +

Another example Homolytic fission CH3Br  CH3 + Br Heterolytic fission CH3Br  CH3+ + Br- + Carbocation

Cycloalkane cyclopropane cyclobutane cyclopentane cyclohexane Methyl cyclohexane

Alkylamine (R-NH2) CH3NH2 methylamine CH3CH2NH2 ethylamine CH3CH2CH2NH2 propylamine

Alkenes C=C ethene CH2=CH2 CH2=CH-CH3 CH2=CH-CH2-CH3 CH2=CH-CH2-CH2-CH3 CH3-CH=CH-CH2-CH3 Double bond number is the smallest number in the longest carbon chain propene butene pentene pent-2-ene

Isomerism Structural isomer Different structural formula same molecular formula CH3-CH2-CH2-CH3 Butane, C4H10 Methyl propane, C4H10

Prove it ! Functional isomerism Alcohol and eter Aldehid and ketones Ethanol: CH3-CH2-OH, molecular formula: C2H6O Ether : CH3-O-CH3, molecular formula: C2H6O Aldehid and ketones pentanal: ,molecular formula:C5H10O Penta-2-one C5H10O Alkanoic acid and esthers Propanoic acid Methyl ethanoate Prove it !

Stereo isomer Geometric isomer (cis-trans isomerism) But-2ene: CH3-CH=CH-CH3 Cis-but-2-ene trans-but-2-ene

Optical isomerism use 3 dimensional formula Occurs in the chiral molecules The star sign indicate chiral center. Chiral center is the carbon atom which carries four different groups Butan-2-ol

Reactions Routes Write the reactions routes to convert: Propene to propanol pass propene and steam over heated phosphoric acid catalyst under pressure b. Propene to propanal pass propene and steam over heated phosphoric acid catalyst under pressure untill propanol forms Distill on propanol to acidified potassium dichromate

O C C-C-C-C-C-C-C-C C Br Br Draw the structure of 5,7 dibromo, 2,6 dimethyl octan-3-one Solution steps Draw the longest chain Give the number Put the function Put the branches O C 1 2 3 4 5 6 7 8 C-C-C-C-C-C-C-C C Br Br