Synthesis of pyranotropanes via enantioselective deprotonation strategy

✍ Scribed by Marek Majewski; Ryszard Lazny

• Book ID: 104214288
• Publisher: Elsevier Science
• Year: 1994
• Tongue: French
• Weight: 279 KB
• Volume: 35
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(00)73063-2

✦ Synopsis

Synthesis of tropane alkaloids darlingine, chalcostrobamine and isobellendine both in the racemic form and as unnatural enantiomers is described. Enantioselective deprotonation of tropinone, which proceeded with ca 90% ee, was the key step in each of the syntheses. Enantioselectivity was increased in the presence of LiCl.

Deprotonation of cyclic ketones with chiral lithium amide bases is a promising new synthetic tool.