Reaction of α‐lithio O‐alkyloximes with diiodomethane – a synthesis of α‐iodomethylene oxime ethers

Regiocontrolled deprotonation (e. g. lithiation) of acetone O‐methyloxime (1), 5,6‐dihydro‐3‐methyl‐4H‐1,2‐oxazine (9a) and 4,5‐dihydro‐3‐methylisoxazole (9b) is achieved within 1 minute at −65°C in hexane/THF. The lithiated compounds react very fast at low temperature (−65°C) with diidomethane to give mainly the corresponding α‐iodomethylene oxime ethers 6 and 11a, b. A radical mechanism of this reaction is discussed.