Diazonamide Support Studies: Stereoselective Formation of the C10 Chiral Center in both the CDEFG and AEFG Fragments
摘要:
The synthesis of both the AEFG macrolactam and the CDEFG bis-indole/tyrosine units found in the marine natural product diazonamide A is presented. Key to the success of the synthesis is the highly stereoselective direct C-arylation of an oxindole by an aryllead(IV) reagent derived from tyrosine.
Structural Characterization of an Enantiomerically Pure Amino Acid Imidazolide and Direct Formation of the β-Lactam Nucleus from an α-Amino Acid
摘要:
Decomposition of a diazo beta-ketoamide derived from N-trityl serine imidazolide and N-protected acetanilides provides, instead of the expected beta-acyloxindole product, an enantiomerically pure (EP) beta-lactam. The amino acid stereocenter is incorporated, the second chiral center is induced, and trityl protection of the beta-lactam ring is realized for the first time. The desired beta-acyloxindole is obtained from oxindole and Tr-Ser(OBn)-imidazole, the X-ray of which provides the first structural determination of an EP amino acid imidazolide.
Structural Characterization of an Enantiomerically Pure Amino Acid Imidazolide and Direct Formation of the β-Lactam Nucleus from an α-Amino Acid
作者:Brian S. Gerstenberger、Jinzhen Lin、Yvette S. Mimieux、Lauren E. Brown、Allen G. Oliver、Joseph P. Konopelski
DOI:10.1021/ol7025922
日期:2008.2.1
Decomposition of a diazo beta-ketoamide derived from N-trityl serine imidazolide and N-protected acetanilides provides, instead of the expected beta-acyloxindole product, an enantiomerically pure (EP) beta-lactam. The amino acid stereocenter is incorporated, the second chiral center is induced, and trityl protection of the beta-lactam ring is realized for the first time. The desired beta-acyloxindole is obtained from oxindole and Tr-Ser(OBn)-imidazole, the X-ray of which provides the first structural determination of an EP amino acid imidazolide.
Diazonamide Support Studies: Stereoselective Formation of the C10 Chiral Center in both the CDEFG and AEFG Fragments
作者:Jinzhen Lin、Brian S. Gerstenberger、Nhu Y T. Stessman、Joseph P. Konopelski
DOI:10.1021/ol8014336
日期:2008.9.18
The synthesis of both the AEFG macrolactam and the CDEFG bis-indole/tyrosine units found in the marine natural product diazonamide A is presented. Key to the success of the synthesis is the highly stereoselective direct C-arylation of an oxindole by an aryllead(IV) reagent derived from tyrosine.