142592-66-3Relevant academic research and scientific papers
Gram-scale synthesis of iejimalide B
Gagnepain, Julien,Moulin, Emilie,Fuerstner, Alois
, p. 6964 - 6972 (2011/07/30)
IejimalideB (2) is the most promising member of a small family of marine polyene macrolides endowed with remarkably selective activity against human cancer cell lines. As this product, however, is hardly available from the natural sources, a detailed evaluation requires the development of an efficient and practical synthetic approach. This challenge has now been met by adapting the first total synthesis of 2 previously reported by our group to the needs of high material throughput. Redesigning the access routes to the five required building blocks in combination with a careful optimization of the fragment coupling processes provided gram amounts of this valuable compound in a sequence of no more than 16 linear steps with an overall yield of about 7 %. Key elements of the successful strategy include: i) three hydrostannylation processes of elaborate terminal alkynes with "lower order" stannyl cuprates, ii) a Brown allylation, a Noyori transfer hydrogenation, and a Marshall propargylation to set the chiral centers at C9, C17, C22 and C23, and iii) a modified Takai-Utimoto olefination for the preparation of the very labile skipped 1,4-diene flanking the ester group. The assembly process benefited from a particularly mild protocol for the Stille cross-coupling previously developed in this laboratory, which clearly outperformed the alternative Suzuki reaction in terms of yield and scalability. The 24-membered macrocyclic frame was forged by a remarkably selective ring-closing metathesis reaction (RCM), in which two out of the ten double bonds present in the cyclization precursor were selectively activated with the aid of a second-generation Grubbs catalyst. Copyright
Total synthesis of the ionophore antibiotic CP-61,405 (routiennocin)
Diez-Martin, David,Kotecha, Nikesh R.,Ley, Steven V.,Mantegani, Sergio,Menendez, J. Carlos,Organ, Helen M.,White, Andrew D.,Banks, Bernard J.
, p. 7899 - 7938 (2007/10/02)
The total synthesis of the spiroketal ionophore antibiotic routiennocin 1 (CP-61,405) employing π-allyltricarbonyl iron lactone complexes is described. These complexes were used as precursors for the preparation of substituted 2-phenylsulphonyl pyrans whi
