methyl acetylene in 1,2-dichloro-ethane byproducts: hexyne, 1-chloro-1-hexene, hexenyl phosphonium salts; evacuated and N2 added two times; dichloroethane and propyne addn.; evacuated until boiled at room temp., and N2 added rapidly; cycle repeated;cooled to -78°C, tube sealed; refluxed 2 h; decane added; distd. the volatiles; residue recrystd. from dichloroethane;

RhCl(PPh3)3 in 1,2-dichloro-ethane 24 h; other solvents, reagent ratio; Product distribution;

thionyl chloride in N,N-dimethyl-formamide 1.5 h; Heating;

1: 71 percent / pyridine 2: thionyl chloride / CH2Cl2 / 1 h / Heating View Scheme

1: AgCN / benzene / 4 h / Heating 2: 1.) CuI*P(Bu)3; 2.) BF3*Et2O / 1.) -78 deg C, 30 min, Et2O; 2.) Et2O-THF (4:1) -78 to -40 deg C, 20 h 3: 1N NaOH / aq. ethanol / Heating View Scheme