Alkyne and Alcohols rxns

1. XS NaNH2 in NH3

2. H2O

(to an alkane)

Creates an alkyne from and alkane, the 2nd step protonates the negative charge, tends to give a terminal alkyne

Molten KOH

(to an alkane)

Creates an alkyne from an alkane, give an internal alkyne

H-X (1 eq)

• Creates an alkene from the akyne and adds X to one side and H to the other side

• Called hydrohalogenation

XS H-X (2 eq.)

• Creates an alkane from the alkyne and adds the 2 X’s to the same carbon and the 2 H’s to the same carbon

• hydrohalogenation

• Regio: Markovnikov (will be anti-mark if added with peroxide)

• Mechanism need to know

HgSO4 in H2SO4, H2O

• Creates an alkane from the alkyne and adds -OH to one side of alkene and -H to the other side

• The -OH turns into a ketone via keto-enol tautomerism (thanks to the H2O)

• Will use acid catalyzed keto-enol tautomerism (need to know mechanism)

• Regio: Markovnikov

H2 /Pt

• Reduction of an alkyne fully to alkane

• Catalytic hydrogenation

H2/Lindlars

• partial reduction of the alkyne to the alkene

• Gives the cis alkene

Na in NH3

• partial reduction of an alkyne to an alkene

• gives the cis alkene

• Metal-ammonia reduction

1. Sia2BH • THF

   H2O2, NaOH

Reduction of the alkyne to an alkene, adds the Sia2B (replaced by -OH) to the less substituted carbon (anti-mark), and then undergoes base catalyzed keto-enol tautomerism

KMnO4, H2O neutral

• reduces alkyne to diketones, gives 4 -OHs initiallly, but then 2 H2Os are removed to produced diketones

• to a terminal alkyne will give a ketone and a carboxylic acid

KMnO4, KOH in H2O, heat

• cleaves the triple bond and gives to carboxylic acids

• will initially produce two carboxide ions which will be protonated to two carboxylic acids

NaH • THF

• will create an alkoxide ion

• R-O-H + NaH → R-O^- + Na⁺ + H2

• Will create a strong nucleophile

Addition of H3O⁺ to alkenes

• will add an -OH to the more substituted carbon, carbocation potenial rearrangements

• Regio: Markovnikov

1. Hg(OAc)2, H2O

2. NaBH4

• oxymercuration demurcuration

• regio: markovnikov

• adds an -OH to the more substituted carbon

1. BH3 • THF

2. H2O2, NaOH

• hydroboration oxidation

• adds -OH to the less substituted carbon

• Regio: Anti-mark

1. O3

2. Et2S (dimethylsulfide)

• will cleave the double bond in alkenes to produce  ketones and aldehydes

• Mechanism —> carbon will attack the O with the double bond, double bonded O electrons will go to the center O, the single bonded O (with charge) will attack the carbon/alkene

KMnO4, OH^- (cold, dilute)

• SYN dihydroxylation

• will at -OH to both sides of the akene onto the same side (either both wedges or both dashes)

OsO4, H2O2

• SYN dihydroxylation

• will at -OH to both sides of the akene onto the same side (either both wedges or both dashes)

mCPBA (RCOOH), H3O⁺ (to alkene)

• ANTI dihydroxilation

• creates an epoxide first, then the acid will break the epoxide ring and give an anti dihydroxylation

1. Mg, ether

2. H3O⁺

• creates a grignard reagents which insterts itself between the halide and the carbon

• can attack carbonyl compounds via Sn2 (???) and give an alcoxide, which si protonated by H3O and turn alcohol + extend the carbon chain

• addition to acid chlorides or esters will give a tertiary (3º) alcohol because the reaction will occur twice

1. 2Li, ether

2. H3O

• creates an organolithium reagent

• will react the same as a grignard

CuI

• 2R-Li + CuI —> R2CuLi + LiI

• makes the gilman reagent

• Will attack carbonyl compounds to extend the chain and create an alkoxide ion, which will be protonated by the acid workup (H3O) to give an alcohol

1. LiAlH4, ether

2. H3O+

• hydride from the compound attacks carbonyl compounds to create alkoxide ion, which is then protonated to an alcohol

• This is a strong reducing agent and will reduce ketones, aldehydes, esters, and carb acids

• will reduce esters and carb acids to 1º alcohols

1. NaBH4, ether

2. H3O

• reduces ketones and aldehydes to alkoxides and then turns them into alcohols (with acid workup)

• does not react with esters or carboxylic acids

• can take place in a variety of solvents, like alcohols, ethers, and water

Raney Nickel

• reduces a ketone to an -OH, as well as any alkenes to alkanes

• catalytic hydrogenation

H-S

• thiol

• will react with alkyl halide (H-X) to create R-SH (the thiol)

• thiols can be oxidized by mild oxidizing agents to disulfides that can be reduced back to thiols with a reducing agent

• oxidation with strong oxidizing agenst (ex. KMnO4, HNO3, or NaOCl) converts thiols into sulfonic acids

Na2Cr2O7, H2SO4 (secondary alcohols)

• will reduces secondary alcohols to ketones

• PCC and NaOCL/HOAc will do the same

Na2Cr2O7, H2SO4 (primary alcohols)

• will reduce primary alcohols to carboxylic acids

PCC or NaOCl/TEMPO

• will reduce primary alcohols to aldehydes

DMSO, (CO)Cl2 in ET3N, CHCl2

• swern oxidation

• reduces alcohols to aldehydes

TsCl, pyr

• Tosylate esters add to where there is an OH group to make OTs, which is a VERY good leaving group (bulky)

• no interconversion when this occurs

• can be used for Sn2 or E2

Reduction of alcohols

• dehydrate it with H2SO4, then at H2/Pt

• make a tosylate the reduce it with LiAlH4 (R-OTs + LiAlH4 —> R-H, an alkane)

ZnCl2, HCl (concentrated)

• Lucas reagent

• secondary and teriary alcohols react with the lucas reagent via Sn1, primary react via Sn2

• Addition of a lewis acid, such as ZnCl2 will bond strongly with OH, promoting the reaction

• this will replace an alcohol with a Cl

PCl3, pyr

• alcohol will attack the phosphorus, displacing one of the halides

• Cl will attack at the back (Sn2) 

PBr3

• alcohol will attack the phosphorus, displacing one of the halides

• Br will attack at the back (Sn2) 

P/I2

• alcohol will attack the phosphorus, displacing one of the halides

• I will attack at the back (Sn2) 

SoCl2 (thionyl chloride)

• will give retention of configuration if PYR IS NOT PRESENT

• will replace the -OH on the carbon with a Cl and also create SO2 and HCl

(go over pinacol rearrangement)

• dehydration of two OH with H2SO4, but due to carbocation rearrangement will give a ketone

1. OsO4, H2O2

2. HIO4

• periodic acid cleavage of glycols

• oxidatively cleaves glycols (-OH’s that are right next to each other) to crate ketones and aldehydes

Alcohol + carboxylic acid in H2SO4

• esterification

• will produce an ester

Alcohol + acyl chloride in pyr (???)

• esterification

• will produce an ester in higher yield and HCl will be a by-product

Williamson ether synthesis

Na and R-O^- + R-CH2-X —> R-O-CH2-R + NaX

• ethers can be synthesized by the rxn of alkoxide ions with primary alkyl halides