Figure 5
From: “Cation-Stitching Cascade”: exquisite control of terpene cyclization in cyclooctatin biosynthesis
Regioselective synthesis of the deuterated GGDPs.
(A) Reaction conditions: (a) LiAlD4 (1.0 equiv.), Et2O, −60 °C, 0.5 h; (b) EtO2C–C(CH3) = PPh3 (1.2 equiv.), CH2Cl2, rt, 1 h; (c) LiAlH4 (1.5 equiv.), Et2O, −40 to −20 °C, 1 h; (d) CBr4 (1.3 equiv.), PPh3 (1.3 equiv.), CH2Cl2 rt, 0.5 h; (e) Sulfone-A (1.5 equiv.), t-BuOK (4.0 equiv.), THF, −20 °C, 1 h; (f) TBAF (4.0 equiv.), THF, rt, 3 h; (g) LiBHEt3 (5.0 equiv.), Pd(dppp)Cl2 (5.0 mol%), THF, 0 °C, 1 h. (B) Reaction conditions: (a) PCC (2.0 equiv.), CH2Cl2, rt, 3 h; (b) EtO2C–C(CH3) = PPh3 (1.2 equiv.), CH2Cl2, rt, 2 h; (c) LiAlH4 (1.5 equiv.), Et2O, −40 to −20 °C, 1 h; (d) CBr4 (1.3 equiv.), PPh3 (1.3 equiv.), CH2Cl2 rt, 0.5 h; (e) Sulfone-B (1.5 equiv.), t-BuOK (4.0 equiv.), THF, −20 °C, 1 h; (f) TBAF (4.0 equiv.), THF, rt, 3 h; (g) LiBHEt3 (5.0 equiv.), Pd(dppp)Cl2 (5.0 mol%), THF, 0 °C, 2 h.
