The enantiospecific synthesis of (+)-monomorine I using a 5-endo- trig cyclisation strategy

• Malcolm B. Berry,
• Donald Craig,
• Philip S. Jones and
• Gareth J. Rowlands

Beilstein J. Org. Chem. 2007, 3, No. 39, doi:10.1186/1860-5397-3-39

• groups and an intramolecular reductive amination reaction we were able to prepare (+)-monomorine I in just 11 steps from commercially available D-norleucine in a completely stereoselective manner. Background The abundance in natural products and drug candidates of saturated five-membered heterocycles

• findings described above dictated that an alternative cyclisation strategy be investigated. It was anticipated that intramolecular reductive amination of a pendant methyl ketone would furnish the correct diastereoisomer, because the hydride source would be expected to approach the iminium ion from the less

• intramolecular reductive amination to give the desired indolizidine 26-syn as a single diastereoisomer in 18% yield for the two steps. Whilst the yield of this unoptimised reaction was not satisfactory, we were pleased to observe that only the desired diastereoisomer was formed. Oxidation of the terminal alkene

Synthesis and glycosidase inhibitory activity of new hexa- substituted C8-glycomimetics

• Olivia Andriuzzi,
• Christine Gravier-Pelletier,
• Gildas Bertho,
• Thierry Prangé and
• Yves Le Merrer

Beilstein J. Org. Chem. 2005, 1, No. 12, doi:10.1186/1860-5397-1-12

• subsequent reductive amination. This strategy involving the nucleophilic opening of a cis-cyclic sulfate by sodium azide is to our knowledge the first example in C8-series. It revealead to be an efficient alternative to the nucleoplilic opening of an epoxide moiety which proved unsuccessful in this

• purification by ion-exchange chromatography, the targeted aminocyclitol 15 [20] (95% overall yield from 11). Alternatively, to obtain an analog of voglibose, the amine function of 13 could be alkylated via a reductive amination [39] with a dihydroxyacetone derivative. Thus, treatment of the amine 13 by the

• . According to this strategy and to the nature of the ketones involved in the final reductive amination, various aminocyclitols could be synthesized. Thus, in this study two carbasugars and four aminocyclitols were obtained. Biological evaluation of these compounds towards 24 commercially available