“…(+)-Eburnamonine (857) was derived from 860, and (À)-858 was synthesized starting with 859 through the Pictet-Spengler reaction and reductive ring opening of the quaternary salt (Scheme 178). 271,272 g-Pyrone-containing indole alkaloid pleiomaltinine (862) was derived from the natural alkaloid pleiocarpamine. The key Scheme 163 Reagents and conditions: (i) CH 2 ]CHMgBr, CuI, À70 C to À20 C; (ii) LiEt 3 BH, THF, 0 C: (iii) Ph 3 P, I 2 , imidazole, THF, rt; (iv) Zn, ethyl 2-(bromomethyl)acrylate, CuCN, TMSCl, 1,2-dibromoethane, DMF; (v) Grubbs' 2 nd generation catalyst, toluene, 80 C; (vi) POCl 3 , toluene, 80 C; (vii) NaBH 4 , EtOH, 0 C; (viii) TFA, CH 2 Cl 2 , rt.…”