Orgo I: Chapter 9: Alkynes: An Introduction to Organic Synthesis

where does numbering begin in alkynes

nearer the triple bond unless there is a choice between double and triple than double bond receives the lower number

how can alkynes be prepared from alkyl halides

twofold dehydrohalogenation, elimination of HX via treatment with an excess of strong base (KOH NaNH2)

vicinal

substituents attached to adjacent carbons

which catalyst leads to the markovnikov product in hydration of alkynes

HgSO4

Which hydration sequence produces the non-markovnikov product

hydroboration-oxidation

what is the product of markovnikov hydration of an alkyne

ketone

what is the product of hydroboration-oxidation of an internal alkyne

ketone

what is the product of hydroboration-oxidation of an terminal alkyne

aldehyde

what is the solvent for hydroboration-oxidation

BH3 THF & H2O2 H2O NaOH

how are alkynes reduced

H2 and metal catalyst (Pd/C) for complete lindlar catalyst for incomplete (just to alkene stage)

does hydrogenation yield a cis or trans product

cis

how can you reduce an alkyne to a trans alkene

Na or Li in NH3

what are the products obtained from cleavage of internal alkynes

carboxylic acids

what are the products obtained from cleavage of terminal alkynes

carboxylic acid and co2

what are the reactants for oxidative cleavage of alkynes

KMnO4 or O3

pKa of alkane

60

pKa of alkene

44

pKa of alkyne

25

acetylide alkylation

treat first with NaNH2, NH3, then react with 1-bromo alkane chain