One‐Carbon Ring Expansion of Cycloalkanones to Conjugated Cycloalkenones: 2‐Cyclohepten‐1‐One

One-carbon ring expansion of cycloalkanones to conjugated cycloalkenones: 2-cyclohepten-1-one intermediate: 1-trimethylsilyloxycyclohexene reactant: 18.5 g. (0.146 mole) of diethylzinc reactant: 40.2 g. (0.150 mole) of diiodomethane intermediate: 1-trimethylsilyloxybicyclo[4.1.0]heptane product: 2-cyclohepten-1-one byproduct: 3-chlorocycloheptanone Keywords: annulation, carbocyclic-[3]; cleavage, oxidative; cyclization, free radical-carbenoid/nitrenoid; elimination, dehydrohalogenation; diethyl ether; N,N-dimethylformamide; triethylamine; diethylzinc, pyrophoric; diethylzinc, disposal; syringe, gas-tight