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15 Cards in this Set
- Front
- Back
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two main methods for making alkenes
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1. carbon carbon bond formation of acetylene and terminal alkynes
2. functional grp transformation via elimination |
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to make primary/ terminal alkyne from acetylene (c triple bond C) this only works with primary alkyl halides
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1. NaNH2, NH3 ( this step takes off H from one end of C triple bond C (Deprotonation)
2. primary Br with whatever you want to attach to it will attach to where H was ripped off in first step leaving u with terminal alkyne |
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if you want to change both sides of triple bond have to do it twice1. NaNH2, NH3/2. Br....( whatever ur adding )
then a second time 1. NaNH2/NH32. Brwhatever adding ( this adds to other side of triple bond |
know
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vicinal di halides
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both halogens on adjacent carbons
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germinal di halides
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both halogens off same carbon
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germinal dihalide to form alkyne
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have to use 3 equivalents
1. 3NaNh2, NH3 2. H20 |
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hydrogenation of alkynes
to go from alkyne to alkane alkyne + 2H2/ catalyst pd,pt |
alkane
same as for alkenes but need 2 eq of H2 |
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lindlars palladium
alkynes to cis alkenes alkyne + lindlars Pd----> |
forms cis alkenes hydrogens on same face of double bond
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metal ammonia reduction of alkynes
alkyne+ Na, Nh3 can be Na, Li, K) |
forms trans alkenes
H will be trans on double bond |
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addition of hydrogen halides to alkynes
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same as alkenes
follows Markovnikovs rule |
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to form geminal dihalide from alkyne need two eq of hydrogen halide
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also follows Markovnikovs
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alkyne + HBr/ peroxides--->
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anti markovnikov alkene bromide just like alkene rxn
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hydratîon of alkynes
alkyne + H20, H+ ---->enol alkyne + 1. H20, H+ 2. HgSO4---> ketone |
enol the expected product which is H on one side double bond OH on most subst C. a ketone is more stable then enol so to male ketone as major product you do 2 step
1. H20, H+ 2. HgS04 ( c double bond O will be on most sub C and the other hydrogen added of least sub) |
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addition of halogens to alkynes
1. alkyne + 2 eq of Cl2-----> 2. alkyne + 1 eq of br 2 -----> |
1. will produce alkane with cl attached to eac carbon around triple bond, no stereochemistry or regioselectiveness
2. anti addition br around double bond |
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ozonolysis of alkynes 1.03
2. water gives |
2 carboxylic acids
add c double bond o, oh to each piece rcooh) |
