Hi. I'm having trouble figuring out the allowable reactions for halogenating an alkene.
If I want to do a Markovnikov addition with one halogen, there seems to be a basic ionic addition, where an H and Br is added. Does this apply to the rest of the halogens, like HCl and HI? If I wanted to add anti-Markovnikov, there is free radical addition, which only applies to HBr because only Br has the correct energy to do it. What about the other halogens - how would I add them anti-markovnikov?
If I wanted to do an anti-addition of two halogens (like Br2) then I would use addition of halogens, where one Br forms that triangle thing (I forgot what it's called), then the other Br attacks from behind, to give anti. Is this correct, and does it apply to the rest of the halogens? Also, is there a reaction to give a syn addition? I couldn't seem to find one in my textbook. For removal of one halogen, I could do an E2 reaction, correct? And to remove 2 halogens which are anti to each other, I could use a reaction called Dehalogenation of Vicinal halogens, I think. Is this also correct?