Enantioselective total synthesis of (-)-colchicine, (+)-demecolcinone and metacolchicine: determination of the absolute configurations of the latter two alkaloids.

Enantioselective total synthesis of (–)-colchicine, (+)-demecolcinone and metacolchicine: determination of the absolute configurations of the latter two alkaloids† †Electronic supplementary information (ESI) available. CCDC 1547674 and 1524362. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c7sc01341h Click here for additional data file. Click here for additional data file.

Two new tropolonic alkaloids from Colchicum speciosum Steven bulbs

Background and objectives: The genus Colchicum belongs to the family Colchicaceae, which comprises of 19 genera, and 225 species worldwide. They have been recognized for more than 2000 years for their noticeable biological properties. The Colchicum species are well known for presence of tropolonic alkaloids, mainly colchicine. Colchicine, is still the drug of ...

Three-component procedure for the synthesis of new chiral spirooxindolopyrrolizidines via catalytic highly enantioselective 1,3-dipolar cycloaddition

The catalytic highly regio-, diastereo-, and enantioselective synthesis of a small library of spiropyrrolizidineoxindolesvia a four-component 1,3-dipolar cycloaddition reaction of azomethine ylides, derived from isatin, with electron-deficient dipolarophilewas described. The process occurs at room temperature in aqueous ethanol as a green solvent and in the presence of a bidendatebis(imine)–Cu(...

Chemoenzymatic Enantioselective Formal Synthesis of (-)-Gephyrotoxin-223

(-)-Gephyrotoxin-223 was formally synthesized from chiral synthon 1 which has been chemoenzymatically synthesized  in the presence  of Candida Antartica lipase.        

Three-Component Procedure for the Synthesis Chiral Spirooxindolopyrrolizidines via Catalytic Highly Enantioselective 1,3-Dipolar Cycloaddition of Azomethineylides and 3-(2-Alkenoyl)-1,3-Oxazolidin-2-ones

The catalytic highly regio-, diastereo-, and enantioselective synthesis of a small library of spiropyrrolizidineoxindolesvia a four-component 1,3-dipolar cycloaddition reactionof azomethineylides, derived from isatin, with electron-deficient dipolarophilewas described. The process occurs at room temperature in aqueous ethanol as a green solvent and in the presence of a bidendatebis(imi...