Hydrocarbons: Named Reactions and Reagents at a Glance

Reaction Name	Discoverer/Name	Reagents	Substrate	Product	Special Feature
Markovnikov Addition	Vladimir Markovnikov (1869)	HX (no peroxide)	Alkene	More substituted alkyl halide/alcohol	H → more-H carbon; stable carbocation
Kharasch Effect	Morris Kharasch (1930s)	HBr + ROOR	Alkene	Less substituted alkyl halide	ONLY HBr + peroxide; free radical
Free Radical Halogenation	—	$X_{2}$ / UV or $\Delta$	Alkane	Alkyl halide	Chain: init→prop→term
Ozonolysis (Reductive)	Criegee mechanism	$O_{3}$ then Zn/ $H_{2}O$	Alkene	Aldehydes + Ketones	Cleaves C=C; locates double bond
Ozonolysis (Oxidative)	—	$O_{3}$ then $H_{2}O$ _{2}	Alkene	Carboxylic acids + Ketones	Oxidizes aldehyde fragments further
Lindlar Reduction	Lindlar (1952)	$H_{2}$ , Pd/CaC $O_{3}$ , Pb(OAc)_{2}, quinoline	Internal alkyne	cis-Alkene	Syn-addition; stops at alkene
Birch-type (alkyne)	Birch/dissolving metal	Na or Li, liq. $NH_{3}$	Internal alkyne	trans-Alkene	Anti-addition; radical anion mechanism
Acetylide Formation	—	NaN $H_{2}$	Terminal alkyne	Sodium acetylide RC≡ $C^{-}$$Na^{+}$	Acidity of sp C–H; pKa ~25

Reagent	Purpose	Key Result
UV / hν	Initiates free radical halogenation	Homolysis of $X_{2}$
Organic peroxide (ROOR)	Initiates Kharasch effect (HBr only)	Anti-Markovnikov addition of HBr
Zn/ $H_{2}O$	Reductive ozonolysis workup	Aldehydes and/or ketones
Lindlar's catalyst	Partial alkyne hydrogenation	cis-Alkene (syn-addition)
Na/liq. $NH_{3}$	Dissolving metal alkyne reduction	trans-Alkene (anti-addition)
NaN $H_{2}$	Deprotonates terminal alkyne	Sodium acetylide (nucleophile)