Incubation of [6-H-2]FPP (14a) with epicubenol synthase isolated from Streptomyces sp. LL-B7 gave epicubenol (1c) labeled at D-9 as established by 2H NMR. These results confirm the involvement of a predicted 1,2-hydride shift in the mechanism of formation of 1.
Incubation of [6-H-2]FPP (14a) with epicubenol synthase isolated from Streptomyces sp. LL-B7 gave epicubenol (1c) labeled at D-9 as established by 2H NMR. These results confirm the involvement of a predicted 1,2-hydride shift in the mechanism of formation of 1.
Evolution of a Polyene Cyclization Cascade for the Total Synthesis of (−)-Cyclosmenospongine
作者:Klaus Speck、Thomas Magauer
DOI:10.1002/chem.201605029
日期:2017.1.23
We report a full account on the development of a unique cationic polyenecyclization for the total synthesis of the tetracyclic meroterpenoid (−)‐cyclosmenospongine. A highly convergent three‐component coupling strategy enabled rapid access to individual cyclization precursors that were tested for their reactivity. The successful transformation generates three rings and sets four consecutive stereocenters
Triterpenoid total synthesis. Synthesis and absolute configuration of mispyric acidTriterpenoid total synthesis. Part 8. For part 7 see ref. 1
作者:Yusuke Imamura、Hirosato Takikawa、Mitsuru Sasaki、Kenji Mori
DOI:10.1039/b406820c
日期:——
The first synthesis of mispyric acid (1), an inhibitor of DNA polymerase β with a novel triterpene skeleton, was achieved by starting from isoprene (2), geraniol (6) and 1,5-dimethoxy-1,4-cyclohexadiene (14). The absolute configuration of the naturally occurring 1 was determined as 2S,4S.