‹e¡ñNAME_OF_RECdTYPE_OF_RECdSUBSTRATECdREAGENTSCdSOLVENTCdENVIRONMENCdSUBSTRATE_CdPRODUCT_CLCdNOTESCþMECHANIPC9M PRODUCTCdLEAVING_GRCd catalytic hydrogenation alkyne 2 H2 alkynes alkanes syn addition of H2 alkane poisoned catalytic hydrogenation alkyne H2, CaCO3 quinoline Pd alkynes alkenes syn addition of H2 alkene poisoned catalytic hydrogenation alkyne H2, Ni2B alkynes alkenes syn addition of H2 alkene hydrogenation alkyne Li, RNH2 alkynes alkenes anti addition of H2 alkene hydrohalogenation alkene HBr ROOR alkenes alkyl halides anti-Markovnikov addition 1º alkyl halide hydrohalogenation alkene Cl2 CCl4 500ºC alkenes alkyl halides allylic substitution 1º alkyl halide hydrohalogenation alkene NBS CCl4 hv alkenes alkyl halides allylic substitution 1º alkyl halide hydrohalogenation alkene NBS CCl4 ROOR alkenes alkyl halides allylic substitution 1º alkyl halide hydrohalogenation alkene HX alkenes alkyl halides Markovnikov addition 2º alkyl halide hydrohalogenation alkene HX alkenes alkyl halides Markovnikov addition 3º alkyl halide hydrobromination hydrohalogenation alkene HBr ROOR alkenes alkyl halides 3º alkyl bromide halogenation alkyne X2 CCl4 alkynes alkyl halides anti addition via halonium ion dihaloalkene halogenation dihaloalkene X2 CCl4 alkyl halides alkyl halides anti addition via halonium ion tetrahaloalkane halogenation alkyne 2 HBr alkynes alkyl halides gem-dihaloalkane