1: 65 percent / NaH / toluene / 110 °C View Scheme

1: 65 percent / NaH / toluene / 110 °C 3: 55 percent / rhodium(II) mandelate; other rhodium compounds (rhodium(II) acetate); other temperatures / 1 h / 80 °C / rhodium carbenoid mediated cyclizations, other solvents, other temperatures View Scheme

potassium phosphate; potassium hydroxide in toluene Inert atmosphereReflux;

1: 65 percent / NaH / toluene / 110 °C 3: 40 percent / rhodium(II) mandelate / Heating View Scheme