Opening of cyclic acetals by trichloro-, dichloro-, and tribromo-borane
Abstract
The rate-determining step in the ring opening of cyclic acetals by trichloroborane to yield α-chloro-ethers is shown to be consistent with the formation of an oxocarbenium ion. Subsequent reduction provides a general route for the conversion of a diol into a hydroxy-ether. Tribromoborane is a more powerful and dichloroborane a less powerful reagent than trichloroborane.