A practical access to chiral phenylisoserinates, preparation of Taxotere® analogs
摘要:
A practical diastereoselective synthesis of phenylisoserine methyl esters 8a-c is described using alpha-methyl-benzylamine as the chiral template of a Staudinger reaction. Optically pure diastereoisomers 6a-c were easily recovered by crystallization. After opening of these intermediate azetidinones by hydrochloric acid and methanol, regioselective cleavage of the chiral auxiliary was achieved by hydrogenation over palladium. Phenylisoserinates 8b,c were used to prepare analogs of Taxotere(R).
A practical access to chiral phenylisoserinates, preparation of Taxotere® analogs
摘要:
A practical diastereoselective synthesis of phenylisoserine methyl esters 8a-c is described using alpha-methyl-benzylamine as the chiral template of a Staudinger reaction. Optically pure diastereoisomers 6a-c were easily recovered by crystallization. After opening of these intermediate azetidinones by hydrochloric acid and methanol, regioselective cleavage of the chiral auxiliary was achieved by hydrogenation over palladium. Phenylisoserinates 8b,c were used to prepare analogs of Taxotere(R).