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Ch. 9 & 10
Alkyne naming, organohalides, more mechanisms
Term | Definition |
---|---|
Reagents needed for HC triple-bond CH to form CH3CH2CH2CH2CH=O | 1. NaNH2 / NH3 2. CH3CH2CH2Cl 3. BH3 / THF 4. H2O2 / KOH / H2O |
Vicinal dihalide | two halogens on neighboring carbons (example 1,2 diboroalkane) |
True or false: carboxylic acids are more acidic than alkynes | True |
Free radical chlorination of methane, CH4 | CH3(with radical) + Cl (with radical) --> CH3Cl |
What is the reactivity order of alcohols with HCl (gas)/ether/0 degrees C? | Tertiary > secondary > primary > methyl alcohols |
monochlorination (Cl2/ uv light) of 1-methylcyclopropane form how many products? | Forms 3 products! |
Bromination (Br2/uv light) forms how many products? | 1 product! |
What product results from reaction of cyclopentene with NBS /CCl4 / uv light? | 3-Bromocyclopentene |
Allylic carbon | carbon next to a double bond |
Vinylic halide | halogen on a double bond |
Geminal dihalide | halides attached to the same carbon |
Alkyne + 2Br/CCl4 --> | Tetrahalide product |
Alkyne + 2H2/Pd, C --> | Forms alkane |
Alkyne + H2/lindlar catalyst --> | Forms cis-alkene |
Alkyne + Na/liquid NH3 --> | Forms trans-alkene |
Oxidative cleavage of a terminal alkyne | Forms a carboxylic acid and a CO2 |
Oxidative cleavage of internal alkyne | Forms two carboxylic acids |
Oxidative cleavage reagents | KmnO4/H+ or O3/Zn, H+ |
Rank alkyne acidity | Alkyne > Alkene > Alkane |
Why are alkynes more acidic than alkanes? | Conjugate base of alkyne is stronger |
Reagents of alkyne mercuration-demercuration... | 1. HgSO4 2. H2O/H2SO4 |
Reagents of alkyne hydroboration... | 1. BH3/THF 2. H2O2/KOH |
How to rank hydrogens by increasing acidity | Since acidity is directly related to the electronegativity of the central atom, the hydrogen atom attached to oxygen will be the most acidic, followed by the one attached to nitrogen, and then the one attached to sulfur. |
When is a radical most stable? | Allylic radical! (it is on a carbon that neighbors a double bond) |
When is a radical least stable? | Aryl radical (on a cyclo double bond) & vinylic radical (on a carbon double bonded to another carbon) |
Best reagent needed to convert 2-methyl-1-pentanol into 1-chloro-2-methylpentane? | SOCl2 / pyridine |
alkene --> NBS/CCl4/uv light (list intermediate) --> KOH/heat--> (list final product) | intermediate = bromine on carbon that neighbors double bond final product = 1,3 dialkene variant |
Treatment of a cycloheptene with KMnO4 / KOH/H2O results in which of the following products? | cis--1,2-diol |
When an alkene is subjected to treatment with Hg(OAc)2 in CH3OH followed by reaction with NaBH4, what new class of compound is formed? | ether |
In the initiation step of the of free radical chlorination, what mechanism occurs? | A Cl2 dissociates into two radical chlorines |
In the first propagation step of the free radical chlorination of methane, what mechanism occurs? | A chlorine radical abstracts a hydrogen (takes hydrogen away) |
In the 2nd propagation step of the free radical chlorination of methane, what mechanism occurs? | A carbon radical reacts with a chlorine radical |
Describe the third step of free radical chlorination, termination | radical + radical = molecule (two chlorine radicals make Cl2, to carbon radicals join, or a chlorine radical and a carbon radical join) |
Alkyne to alkene with oxygen reagents... | HgSO4, H2O, H2SO4 |
Alkyne to alkene reagents... | 1. Br2 / CH2Cl2 2. excess NaOH / heat |
Leaving group definition | An atom or group of atoms which breaks away from the rest of the molecule, taking with it the electron pair which used to be the bond between the leaving group and the rest of the molecule |
Bad leaving groups | OH is the main one we focused on |
Good leaving groups | The conjugate bases of strong acids (e.g. I-, Br-, Cl-, TsO-, H2O) are good leaving groups |