Alkyne reactions

hydrohalogenation

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hydrohalogenation

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hydrohalogenation

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hydrohalogenation

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hydrohalogenation

anti-mark

halogenation

trans-addition

halogenation

trans-addition

hydration

terminal; product is a methyl ketone, enol is anti-mark

hydration

terminal; product is an aldehyde, enol is anti-mark

keto enol tautomerism

In hydration of alkynes, this is an instantaneous process where the enol rearranges to be more stable

enol

Carbon attached to an alcohol and an alkene; not stable and undergoes KET

hydration

acid-cat, carbocation formed, acid regens, carbonyl

hydration

base-cat, carboanion formed, base regens, aldehyde

hydration

hydration

cleavage

not commonly done on alkynes

hydrogenation

terminal and within give same product

hydrogenation

cis addition, H+ add from same side

hydrogenation

trans addition, H+ add from different side

poisoned cat

Lindlar’s cat, Pd/CaCO3/PbO2, or P-2 cat (Ni2B)
used in hydrogenation to yield alkene with cis-addition

synthesis

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X adds to carbon with less hydrogens

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H+ adds to carbon with more hydrogens

anti-mark

X adds to carbon with more hydrogens

anti-mark

H+ adds to carbon with less hydrogens