Practical Enzymatic Desymmetrization of 2-(Ethoxycarbonyl)propane-1,3-diyl Dihexanoate and Model Cyclization for the A–D Ring System of Lysergic Acid
✍ Scribed by Sachiho Miyata; Takuya Kumamoto; Tsutomu Ishikawa
- Publisher
- John Wiley and Sons
- Year
- 2007
- Tongue
- German
- Weight
- 240 KB
- Volume
- 90
- Category
- Article
- ISSN
- 0018-019X
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
Porcine pancreas lipase‐catalyzed hydrolysis of symmetrical 2‐(ethoxycarbonyl)propane‐1,3‐diyl dihexanoate, under the modified conditions of the Seebach protocol, afforded a desymmetrized monohexanoate in 40–51% yield with 91–94% ee, even in a gram‐scale reaction. The absolute configuration of a half‐hydrolyzed (−)‐product was determined to be (R) by conversion to a known 2‐methylpropane‐1,3‐diol derivative. Samarium iodide‐induced radical cyclization of 2‐oxo‐3‐phenylethylamine with a C~4~ unit on the N‐atom, derived from the racemic monohexanoate, afforded a 3‐phenylpiperidine derivative as a model construction of the A–D ring system of lysergic acid.