200186-35-2Relevant academic research and scientific papers
Spongipyran synthetic studies. Total synthesis of (+)-spongistatin 2
Smith III, Amos B.,Lin, Qiyan,Doughty, Victoria A.,Zhuang, Linghang,McBriar, Mark D.,Kerns, Jeffrey K.,Boldi, Armen M.,Murase, Noriaki,Moser, William H.,Brook, Christopher S.,Bennett, Clay S.,Nakayama, Kiyoshi,Sobukawa, Masao,Lee Trout, Robert E.
experimental part, p. 6470 - 6488 (2011/02/25)
Evolution of a convergent synthetic strategy to access (+)-spongistatin 2 (2), a potent cytotoxic marine macrolide, is described. Highlights of the synthesis include: development of a multicomponent dithiane-mediated linchpin union tactic, devised and implemented specifically for construction of the spongistatin AB and CD spiro ring systems; application of a CaII ion controlled acid promoted equilibration to set the thermodynamically less stable axial-equatorial stereogenicity in the CD spiroketal; use of sulfone addition/Julia methylenation sequences to unite the AB and CD fragments and introduce the C(44)-C(51) side chain; and fragment union and final elaboration to (+)-spongistatin 2 (2) exploiting Wittig olefination to unite the advanced ABCD and EF fragments, followed by regioselective Yamaguchi macrolactonization and global deprotection. Correction of the CD spiro ring stereogenicity was subsequently achieved via acid equilibration in the presence of CaII ion to furnish (+)-spongistatin 2 (2). The synthesis proceeded with a longest linear sequence of 41 steps.
Spongistatin synthetic studies. 1. Construction of a C(29-48) subtarget
Smith III, Amos B.,Zhuang, Linghang,Brook, Christopher S.,Boldi, Armen M.,McBriar, Mark D.,Moser, William H.,Murase, Noriaki,Nakayama, Kiyoshi,Verhoest, Patrick R.,Lin, Qiyan
, p. 8667 - 8670 (2007/10/03)
In this Letter, the first in a series of three, we outline our overall strategy and describe the assembly of a C(29-48) EF-ring advanced intermediate for the total synthesis of the spongistatins, rare and structurally unique polyether macrolides with unpr
