OChem 1 Final

carbon-oxygen sigma bonds

alcohol, ether and epoxide functional groupd contain ____

alcohols

contain a hydrocy group (OH) bonded to an sp³ hydridized carbon

enols and phenols

compounds having a hydroxy group on a sp² hydridized carbon undergo different reactions than alcohols

ethers

have 2 alkyl groups bonded to an oxygen atom

epoxides (oxiranes)

are ethers having the oxygen atom in a 3-membered ring

angle strain

epoxides have ____ making them more reactive than other ethers

sp³

the oxygen atom in alcohols, ethers, and epoxides is ____ hybridized

bent shape

alcohols and ethers have a ____ like that in H2O

diols or glycols

compounds with 2 hydroxy groups

triols

compounds with 3 hydroxy groups

epoxyalkanes, oxiranes, or alkene oxides

epoxides can be named in 3 different ways:

dipole-dipole interaction

alcohols, ethers, and epoxides exhibit ____ because they have a bent structure with 2 polar bonds

hydrogen bonding

alcohols are capable of intermolecular ____. thus, alcohols are more polar than ethers and epoxides

increases

steric hindrance ____ as number of R groups increases

decreases

hydrogen bonding _____ as number of R groups increases

increases

as the ability of hydrogen bond the boilind point ____

soluble

alcohols, ethers, and epozides having < or = 5 C’s are H2O _____

insoluble

alcohols, ethers, and epoxides have > 5 C’s are H2O _____

soluble

alcohols, ethers, and epoxides of any size are ____ in organic solvents

host-guest complex

a crown ether-cation complex

host; guest

the crown ether is the ____ and the cation is the ___

molecular recognition

the ability of a host molecule to biind specific guests

williamcon ether synthesis

the preparation of ethers by Sn2 mechanisms creating alcohols and ethers from nucleophilic substitution

alkoxide salt

is needed to make an ether; can be prepared from alcohols by a bronsted-lowry acid-base reaction

halohydrin

organic compounds that contain booth hydroxy group and a halogen atom on adjacent carbons

intra-

is within the molecule

inter-

is inbetween molecules

dehydration

ia a beta elimination reaction in which the elements of OHand H are removed from the alpha and beta carbon atom respectively

ethers

like alcohols, ___ do not contain a goood leaving group

fewer

ether undergo ___ useful reaction than alcohols

epoxides

have the same type of leaving group as ethers, OR-

Zaitsev rule

when an alcohol has 2 or 3 beta carbons, dehydration is regioselective and follows the ____

E1 dehydration

of 2^o and 3^o alcohols with acid gives clean elimination products without any by-products from form an S_n1 reaction

clean elimination

takes place because the reaction mixture contains no good nucleophile to react with the intermediate carbocartion, so no competing Sn1 reaction occurs

Le Chatelier principle

a system at equilibrium will react to counteract any disturbance to the equilibrium

rearrangement

when carbocation are intermediates, a less stable carobcation will be converted into a more stable carbocation by a shift of a hydrogen or an alkyl group

1,2-hydride shift

movement of a hydrogen atom

1,2-alkyl shift

movement of an alkyl group

1,2-shift

because the migrating group in a ____ moves with 2 bonding electrons, the carbon it leaves behind now has only 3 bonds (6 electrons), giving it a new positive (+) charge

1,2-shift

can convert a less stable carbocation into a more stable carbocation

rearrangements

are not unique to dehydration reactions; can occur whenever a carbocation is formed as a reactive intermediate

POCl₃ and pyridine

a common method to convert alohols to alkenes in place of H₂SO₄ or TsOH; proceeds by an E2 mechanism

patchouli alochol

has been used in perfumery becuase of its exotic fragrance

good leaving group

substitution reaction do not occur with alcohols unless -OH is converted into a _____

increases

the reactivity of hydrogen halides ____ with increasing acidity

SOCl₂ and PBr

primary and 2^o alcohols can be converted to alkyl halides using ____

SOCl₂ (thionyl chloride)

converted alcohols into alkyl chlorides

PBr₃ (phosphorous thribromide)

converts alcohols into alkly bromides

alkyl tosylate

is composed of 2 parts: the alkyl group R,derived from an alcohol; and the tosylate, which is a good leaving group; alcohols can be converted into these

nucleophilic substitution and beta elimination

because alkyl tosylates have good leaving groups, they undergo both ____, exactly as alkyl halides do

mercaptans

thiols are also called

thiols

contain a mercapto group (SH) bonded to a carbon atom; are incapable of intermolecular hydrogen bonds and have lower boiling points and melting points than alcohols with a similat number of carbons

sulfides

contain 2 alkyl groups bonded to a sulfur atom

epoxides

do not contain aleaving group but contain a strained 3-membered ring with 2 polar bonds

-OH, -OR, -CN, -SR, and NH₃

common nucleophiles that open the epoxide ring:

leukotrienes

are synthesized in cells by oxidation of arachidonic acid to 5-HPETE

olefins

alkenes are also called

terminal alkenes

have the double bond at the end of the carbon chain

internal alkenes

have at least one carbon atom bonded to each end of the bouble bond

cycloalkenes

contain a double bond in a ring

cis

cycloalkenes having fewer than 8 carbon atoms have a ____ geometry

trans-cycloalkene

must have a carbon chain longenough to connect the ends of the double bond without introducing too much strain

trans-cyclooctene

is the smallest, isolable tran cycloalkene, but is considerably less stable than its cis form, making it one of the few alkenes having a higher energy trnas isomer

C_nH_2n

an acyclic alkene and cycloalkanes has the generla structural formula ____

unsaturated hydrocarbons

alkenes are _____ becuase they have fewer than the maxium number of hydrogen atoms per carbon

alkenols

compounds that contain boht a double bond and a hydroxy group; the chain (or ring) is numbered to give the OH group the lower number

dienes

compounds with 2 double bonds are named ____

trienes

compounds with 3 double dons are names ____

ehtylene

the simplest alkene, CH2=CH2, named in the IUPAC system as ethene is often called ____

weak van der Waals

most alkenes exhibit only ____ interactions, so their physical properties are similar to alkane of comparable molecular weight

low

alkenes have ____ melting and boiling points

increase

melting and boiling points ___ as the number of carbons increases due to increased surface area

organic solvents; water

alkenes are soluble in ___ and insoluble in ____

ethylene

an industrial starting material for many useful products

triacylglycerols

are hydrolyzed to glycerol and three fatty acids of general structure RCOOH

saturated fatty acids

have no double bonds in their lond hydrocarbon chains, and the opposite have one or more double bonds in their hydrocarbon chains

decreases

as the number of double bonds in fatty acids increases, the melting point _____

kinks

the larger the number of Z double bonds, the more ___ in the hydrocarbon chain; this causes poorer staking and less can der Waals interaction, leading to lower melting points

fats and oils

are both traicylglycerols, but with different physical properties

fats

a traicylglycerol that has a higher melting point and are solids at room temperature

oils

a traicylglycerol that has a lower melting point and are liquids at room temperature

fats

are derived from fatty acids having few or no double bonds

oils

are derived from fatty acids having a larger number of double bonds

saturated fats

are typically obtained from animal sources

unsaturated oils

are common in vegetable sources

syn addition

take place when both X and Y are added from the same side

anti addition

take place when X and Y are added from opposite sides

eletrophilic additions

the reaction made because the electrophilic H end of HX is attracted to the electron-rich double bond

exothermic

addition reaction are ____ because the 2 sigma bonds formed in the product are stronger than the sigma and pi bonds broken in the reactants

Markovnikov’s rule

states that in the addition of HX to an unsymmetrical alkene, the H atom adds to the less substituted carbon atom—that is the carbon that has the greater number of H atom to begin wtih

Hammond postulate

according to the ___, the blue path is faster beause formation of the carbocation is an endothermic process

hydrohalogenation

sometimes new stereogenic centers are formed from _____

hydration

the addition of water to an alkene to form an alcohol

halogenation

the addition of X₂ (X = Cl or Br) to an alkene to form a vicinal dihalide

polarizable

halogens add to pi bonds because halogen are ____

carbocations

are unstable because they have only six electrons that surround carbon

bridged halonium

ions that are unstable because of ring strain

bridged chloronium ion

initial addition of the electrophile Cl+ from (Cl2) occurs from either side of the planar double bond to form ____

halohydrin

treatment of an alkene with a halogen X2 and H2O froms a ____ by addition of the groups of X and OH to the double bond

more substituted

as in the acid catalyzed ring opwning of epoxides, nucleophilic attack occurs at the ___ carbon end of the bridged halonium ion