111692-59-2Relevant academic research and scientific papers
Total Synthesis of (+)-Phyllanthocin. Introduction of Intramolecular Hydroformylation for Complex Molecule Functionalization
Burke, Steven D.,Cobb, Jeffery E.,Takeuchi, Kumiko
, p. 2138 - 2151 (2007/10/02)
A 17-step total synthesis of (+)-phyllanthocin (1a) is described.Application of Sharpless'asymetric epoxidation reaction provided access to the diastereo- and enantiomerically pure epoxy ketone 9, a partner in crossed aldol construction.A notably rapid and high-yielding spiroketal equilibration leading to the tetracyclic intermediate 2 was effected with HF in acetonitrile.A Rh(I)-catalyzed hydroformylation was used to introduce the C3 functionality.Studies of intramolecular delivery of the rhodium nucleus to the concave face of the C3-C4 olefin led to a substantial improvement in yield and regioselectivity over the intermolecular version.
INTRAMOLECULAR PHOSPHINE-DIRECTED HYDROFORMYLATION. APPLICATION TO THE TOTAL SYNTHESIS OF (+)-PHYLLANTHOCIN
Burke, Steven D.,Cobb, Jeffery E.
, p. 4237 - 4240 (2007/10/02)
The temporary incorporation of a coordinating phosphine residue into the tetracyclic phyllanthocin precursor 1a directed the 2-catalyzed hydroformylation of 1d largely to the desired C(3) position .This "intramolecular hydroformylation" strategy substantially improves a key transformation in the total synthesis of (+)-phyllanthocin.
