Skip to main content
. Author manuscript; available in PMC: 2016 Mar 24.
Published in final edited form as: Nat Prod Rep. 2015 Feb;32(2):328–347. doi: 10.1039/c4np00051j

Scheme 8.

Scheme 8

Reagents and conditions (a) 73, MeCHO, MeOH, reflux (90%); (b) TBAF, THF, rt (89%); (c) Ac2O, pyridine, DMAP, rt (93%); (d) TFA, anisole, CH2Cl2, rt; (e) EtOAc, reflux (87%, 2 steps); (f) MeSO2Cl, pyridine, CH2Cl2, 0 °C (91%); (g) (Boc)2O, DMAP, CH3CN, rt (97%); (h) NaBH4, H2SO4, EtOH/CH2Cl2, 0 °C; (i) CSA, quinoline, toluene, reflux (88% in 2 steps); (j) Pd2(dba)3 (5 mol%), P(o-tol)3 (20 mol%), TEA, CH3CN, reflux (83%); (k) NaOH, MeOH/H2O, reflux; (l) Ac2O, pyridine, DMAP, rt (93%, 2 steps); (m) TFA, CH2Cl2, rt; (n) TrocCl, aq. NaHCO3/CH2Cl2, rt (74%, 2 steps); (o) DMDO, MeOH/acetone, 0 °C; cat. CSA (90%); (p) NaBH3CN, TFA/THF, 0 °C (94%); q) TBSCl, imidazole, DMF, rt (92%); (r) guanidinium nitrate, NaOMe, MeOH/CH2Cl2, 40 °C (85%); (s) BnBr, K2CO3, CH3CN, reflux (91%); (t) Red-Al, THF, 0 °C (82%); (u) TMSCN, BF3·OEt2, CH2Cl2, 0 °C (73%); (v) Ac2O, pyridine, DMAP, rt (92%); (w) HF, CH3CN, rt (quant); (x) Dess-Martin periodinane, CH2Cl2, rt (92%); (y) Pd/C, H2, THF, rt (84%).