jo0625608_si_001.pdf (27.78 MB)
Dynamic Diastereoselectivity during Iron Carbonyl Mediated Spirocyclization Reactions
journal contribution
posted on 2007-03-30, 00:00 authored by Anthony J. Pearson, Huikai Sun, Xiaolong WangDynamic diastereoselectivity during Fe(CO)3 promoted [6 + 2] ene spirocyclization of 35a and 35b,
having a chiral center on the pendent side chain, was investigated and gave rise to products 28a and 28b
instead of four possible isomers. From this reaction, two chiral centers are generated, with absolute
stereochemistry determined by the double bond geometry and the chiral center already present. 28a/b
and the diene product from demetallation of 28a are proposed as potential intermediates for total synthesis
of 18-deoxycytochalasin H. Furthermore, a stepwise second cyclization and a tandem double cyclization
mediated by the Fe(CO)3 moiety was investigated.