Synthesis of crispine A analogues via an intramolecular Schmidt reaction

• Ajoy Kapat,
• Ponminor Senthil Kumar and
• Sundarababu Baskaran

Beilstein J. Org. Chem. 2007, 3, No. 49, doi:10.1186/1860-5397-3-49

• indolizidine skeleton using an epoxide initiated electrophilic cyclization of azide as a key step. This novel methodology has been efficiently applied in the stereo- and enantioselective synthesis of indolizidine 167B and 209D (Scheme 1). [16][17][18] Results and discussion In 2002, a new indolizidine alkaloid

Vinylogous Mukaiyama aldol reactions with 4-oxy-2-trimethylsilyloxypyrroles: relevance to castanospermine synthesis

• Roger Hunter,
• Sophie C. M. Rees-Jones and
• Hong Su

Beilstein J. Org. Chem. 2007, 3, No. 38, doi:10.1186/1860-5397-3-38

• aldol strategy for the C-8 and C-8a stereogenic centres of castanospermine is presented using silyloxypyrrole chemistry. The results suggest that a full enantioselective synthesis can be realized provided that C-1 functionalisation is accomplished early in the synthesis, post-coupling. Background N

• destabilization of the intermediate oxocarbenium ion by the adjacent α-ammonium cation. Conclusion In summary, the present work has laid the foundation for a full enantioselective synthesis of castanospermine using a C-8/C-8a disconnection strategy. Future work will focus on C-1 transformation earlier in the

A convenient allylsilane- N-acyliminium route toward indolizidine and quinolizidine alkaloids

• Roland Remuson

Beilstein J. Org. Chem. 2007, 3, No. 32, doi:10.1186/1860-5397-3-32

• trimethylsilylmethylmagnesium chloride addition to ethyl (S)-3-hydroxybutanoate as we described. [50] The first three steps of the enantioselective synthesis were those previously described for the synthesis of racemic compounds (vide supra). Condensation of alcohol 32 with glutarimide under Mitsunobu conditions led to

• constitute the first total synthesis of naturally occurring (-)-lasubine II and (+)-subcosine II and unambiguously establish their absolute configuration as 2S,4S,10S. Allylsilane-N-acyliminium cyclisation. Enantioselective synthesis of (-)-indolizidine 167B by intramolecular allylsilane-N-acyliminium

• by reduction with LiAlH4 of indolizidinones 26. Access to (-)-dendroprimine by catalytic hydrogenation of indolizidinones 26. Synthesis of (±)-myrtine and (±)-epimyrtine. Enantioselective synthesis of (+)-myrtine and (-)-epimyrtine. Synthesis of (±)-lasubines I and II and (±)-2-epilasubine II

The first salen- type ligands derived from 3',5'-diamino- 3',5'-dideoxythymidine and -dideoxyxylothymidine and their corresponding copper(II) complexes

• Daniel Koth,
• Michael Gottschaldt,
• Helmar Görls and
• Karolin Pohle

Beilstein J. Org. Chem. 2006, 2, No. 17, doi:10.1186/1860-5397-2-17

• of diimino functionalized ligands are often used as catalysts for a wide variety of reactions. Enantioselective synthesis has gained in importance in the last few years, and the development of chiral ligands has become an important field in organic chemistry. Nucleosides provide a stable scaffold