Ethers, dichloromethyl methyl anion

There are certain disadvantages to the carbonylation reaction, such as high temperature and pressure. An alternative preparation of trialkylmethanols is the use of the anion of dichloromethyl methyl ether. Addition of this anion to a trialkylborane is followed by three successive migrations to yield the trial-kylmethanol on oxidation. The reaction takes place at room temperature, and tertiary groups migrate without difficulty (Scheme 32). ... 

Chiral boronic esters react with organolithium reagents to form diorganylalkoxyboranes (borinic esters). Subsequent reaction with the anion of dichloromethyl methyl ether then yields chiral ketones by rearrangement of both of the groups on boron (Scheme 42). No racemization is observed in this sequence and alkyl-, aryl- or alkynyl-lithium reagents can be used. 

---