Chemoselective inhibition of the hydrogenolysis of the MPM protective group for phenolic hydroxy functions using a PdC-pyridine catalyst
โ Scribed by Hironao Sajiki; Hiroko Kuno; Kosaku Hirota
- Publisher
- Elsevier Science
- Year
- 1997
- Tongue
- French
- Weight
- 186 KB
- Volume
- 38
- Category
- Article
- ISSN
- 0040-4039
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โฆ Synopsis
A convenient method for the selective hydrogenation of phenolic benzyl ether, Cbz, benzyl ester, nitro and olefin functions distinguishing from the MPM (4-methoxybenzyl) protective group for the phenolic hydroxy groups was accomplished by the addition of pyridine to the PdlC-catalyzed reduction system.
๐ SIMILAR VOLUMES
The benzyl protecting group for hydroxy function was selectively removed by catalytic hydrogenolysis with Raney nickel in the presence of the MPM (4-methoxybenzyl) and DMPM (3,4-dimethoxybenzyl)protecting groups, and applied to the synthesis of some synthons to macrolide and polyether antibiotics.
A mild and chemoselective hydrogenation methodJbr a variety of reducible functional groups distinguishing from aliphatic and aromatic benzyl ethers was accomplished by the addition of an appropriate nitrogen-containing base to the Pd/C-catalyzed hydrogenation system.
Salinomycin was synthesized from D-glucose, D-mannitol, and ethyl L-lactate via coupling of Cl-C9, ClO-C17, and C18-C30 segments. Benzyl-type protecting groups as well as regioand stereoselective reactions played a crucial role.