Scheme 6. Late stage functionalization of 5aAvia oxidative C–C bond formation: (a) (i) CuCl₂ (1 equiv.), THF/MeNO₂ (1 : 1), 25 °C, 3 h; (ii) ⁱPr₂EtN (1.1 equiv.), 25 °C, 2 h. (b) (i) CuCl₂ (1 equiv.), THF, 25 °C, 16 h; (ii) 1-(tert-butyldimethylsilyloxy)-1-methoxyethene (2 + 1 equiv.), 25 °C, 6 h. (c) CuCl₂ (1 equiv.), THF, 25 °C, 16 h; (ii) NaCN (1.5 + 1.5 equiv.), MeOH, 25 °C, 6 h. Insert: stick view of the crystal structure of 6. Hydrogen atoms are omitted for clarity and the CH₂NO₂ chain presents a local disorder.