•
Successive reaction with a Grignard reagent and Li metal leads to 1-substituted cyclopropanols, which rearrange on thermolysis to ethyl ketones: Synthesis, 647 (1983):

• The cyclization can also be induced by ethyl radicals, generated from ethylmagnesium bromide and FeCl3. This method is applicable only to 1-arylcyclopropanols: J. Org. Chem., 29, 2813 (1964); 43, 3602 (1978); Org. Synth. Coll., 5, 1058 (1973).
• Formation of the acetal followed by treatment with NaNH2 provides a route to cyclopropenones: Tetrahedron, 48, 2045 (1992).