A facile, general approach to the synthesis of electrophilic acetone equivalents

The facile, high-yielding, yet general synthesis of electrophilic chloroacetone equivalents 11a-f is described. The enol ethers are assembled in three steps starting with trichloride 29 in overall yields of 57-93%. Nucleophilic displacement of the chloromethyl chlorine with a range of organometallic reagents generates dichlorides 30 in yields of 58-99%, which can be dehydrohalogenated with t-BuOK/THF in yields of 87-99% to produce enol ethers 31. Conversion of the allyl chlorides 31 to the corresponding allyl iodides 11 with 72-99% yield completes the synthetic sequence. The entire sequence can be performed in less than 48 h on a >50 mmol scale.