Multi-step reaction with 3 steps 1.1: samarium diiodide; lithium bromide; tert-butyl alcohol / tetrahydrofuran / 3 h / -40 °C / Inert atmosphere2.1: acetic acid; zinc / 1 h / 80 °C / Sonication3.1: ozone / dichloromethane / -95 °C3.2: 2 h / -95 - 20 °C / Inert atmosphere