Which reaction of an alkene proceeds with anti-addition?

1 Answer
Apr 6, 2018

Too many to list!

Some common ones we often see, are:

  • Anti dihydroxylation (acidic workup after epoxidation)
  • Halogenation (due to the halonium intermediate): if this is carried out in the presence of water or ethers, halohydrin or haloether addition can occur.
  • Oxymercuration-demurcuration (due to the mercurinium intermediate)

Most of these have in common a first step in which concerted syn addition occurs, following by an SN2 step where a nucleophile attacks the more electrophilic carbon (generally Markovnikov regioselectivity).