Four-membered rings Chromium carbene complexes

Nitropropane, 200 Simmons-Smith reagent, 275 Four-membered rings Chromium carbene complexes, 82 Menthol, 172... [Pg.379]

By a photochemically induced elimination of CO, a chromium carbene complex with a free coordination site is generated. That species can coordinate to an alkyne, to give the alkyne-chromium carbonyl complex 4. The next step is likely to be a cycloaddition reaction leading to a four-membered ring compound 5. A subsequent electrocyclic ring opening and the insertion of CO leads to the vinylketene complex 6 ... [Pg.98]