Nicolaou, K. C. published the artcileSynthesis of iso-epoxy-amphidinolide N and des-epoxy-caribenolide I structures. Revised strategy and final stages, Category: ethers-buliding-blocks, the publication is Organic & Biomolecular Chemistry (2006), 4(11), 2158-2183, database is CAplus and MEDLINE.
A general and highly convergent synthetic route to the macrocyclic core structures of the antitumor agents amphidinolide N and caribenolide I has been developed, and the total synthesis of iso-epoxy-amphidinolide N and des-epoxy-caribenolide I structures is described. Central to the revised strategy was the use of a Horner-Wadsworth-Emmons olefination between a β-ketophosphonate and an aldehyde to construct the C1-C13 sector common to both amphidinolide N and caribenolide I. Stereoselective alkylation allowed for the rapid assembly of the complete caribenolide I carbon skeleton. Key steps in the completion of the synthesis of des-epoxy-caribenolide I structure I included hydrolysis of a sensitive Me ester using Me3SnOH, followed by regioselective macrolactonization of the resulting diol seco-acid and global deprotection. An analogous sequence of late-stage manoeuvres was used to arrive at the fully deprotected des-epoxy-amphidinolide N framework, obtained as a mixture of hemiacetal II and its bicyclic acetal. Regio- and diastereoselective epoxidation of the C6 methylene group in the bicyclic acetal provided access to iso-epoxy-amphidinolide N stereoisomer. Several of the prepared compounds were tested for cytotoxicity against human tumor cell lines, and none showed activity.
Organic & Biomolecular Chemistry published new progress about 99438-28-5. 99438-28-5 belongs to ethers-buliding-blocks, auxiliary class Chiral,Aliphatic cyclic hydrocarbon, name is (+)-B-Methoxydiisopinocampheylborane, and the molecular formula is C21H37BO, Category: ethers-buliding-blocks.
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