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A practical synthesis of the lipophilic side chain of the polyoxypeptins
β Scribed by Miguel Lorca; Michio Kurosu
- Book ID
- 104230279
- Publisher
- Elsevier Science
- Year
- 2001
- Tongue
- French
- Weight
- 80 KB
- Volume
- 42
- Category
- Article
- ISSN
- 0040-4039
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β¦ Synopsis
The lipophilic side chain of the cyclic depsipeptide polyoxypeptin A (1) and B (2), strong apoptosis inducers, has been synthesised as an ester of mixed methyl ketal 18. The key step is an asymmetric anti-aldol reaction of the designed 2-(N-2-methylbenzyl-N-2,4,6-trimethylbenzyl) amino-1-phenylpropyl ester 8 by means of a combination of LDA-Cp 2 ZrCl 2 (0.3 equiv.) for enolation and transmetallation into the zirconium enolate for aldolization. By using a non-boron associated anti-aldol reaction, 10 g of the key lactone 6 were synthesised in six steps from 8 and in 48% overall yield.
π SIMILAR VOLUMES
An enantioselective synthesis of the acyl side-chain 3 of polyoxypeptins 1 and 2 was achieved by the Sharpless AE, with subsequent regioselective opening of the epoxyalcohol using a Grignard reagent in the presence of CuI, and an aldol condensation using Seebach's ester. The method reported has the
The first synthesis of the acyl side-chain segment of polyoxypeptin, a potent inducer of apoptosis in human pancreatic carcinoma AsPC-1, was accomplished. The key feature of the present synthesis is the stereospecific palladium-catalyzed hydrogenolysis of (Z)-alkenyloxirane to anti-hydroxyalkenoate
Practical Synthesis of Taxol Side Chain. -A practical large-scale synthesis of the taxol side chain is achieved via the coupling of the chiral imine (V) with ketene acetal (II) followed by sequential reactions of lactamization, demethylation, methanolysis, and N-benzoylation. -(HA, H.-