Skip to main content
. 2020 Feb 6;11(11):3036–3041. doi: 10.1039/c9sc06116a

Scheme 3. Total synthesis of laurendecumallene B (7): (a) allyl acetate (10.0 equiv.), Grubbs 2nd generation initiator (3 mol%), 25 °C, 4 h, 54%, 76% brsm; (b) NaHCO3 (6.0 equiv.), NIS (2.5 equiv.), CH2Cl2, 25 °C, 8 h, 69%; (c) TBSOTf (1.6 equiv.), 2,6-lutidine (4.0 equiv.), CH2Cl2, 0 °C, 1 h, 89%; (d) Raney® nickel (excess), EtOH, 25 °C, 10 min, 72%; (e) Pd/C (0.13 equiv.), H2 (1 atm), EtOAc, 25 °C, 2 h; (f) NaHCO3 (4.0 equiv.), Dess–Martin periodinane (1.1 equiv.), CH2Cl2, 25 °C, 30 min, 92% over 2 steps; (g) TiCl4 (1.0 equiv.), allyltrimethylsilane (1.5 equiv.), CH2Cl2, -78 °C, 30 min, 89%; (h) trans-3-hexene, Grubbs 2nd generation initiator (5 mol%), CH2Cl2, 25 °C, 8 h, 69%, 79% brsm; (i) Boc2O (2.0 equiv.), LiHMDS (1.3 equiv.), THF, −78 to 25 °C, 8 h, 96%; (j) K2CO3 (6.0 equiv.), MeOH, 25 °C, 2 h, 96%; (k) NaHCO3 (4.0 equiv.), Dess–Martin periodinane (1.1 equiv.), CH2Cl2, 25 °C, 30 min, 93%; (l) BDSB (1.2 equiv.), CH2Cl2, 0 °C, 10 min, 38%, 7 : 1 dr; (m) 33 (1.8 equiv.), n-BuLi (1.6 equiv.), THF, 0 °C, 30 min, then 19, THF, 0 °C, <5 min, 58%, 80% brsm, 2 : 1 E/Z; (n) TBAF (2.0 equiv.), THF, 0 °C, 5 min, 81%; (o) BDSB (1.2 equiv.), MeCN, 25 °C, 2 h, 72%, 81% brsm, 1.0 : 1.3 R/S; (p) K2CO3 (10.0 equiv.), MeOH, 25 °C, 2 h, 30% 35, 40% 7.

Scheme 3