✦ LIBER ✦
The C- and D-ring problems of sterol biosynthesis: hydride shift versus carboncarbon bond migration due to conformational changes controlled by counteranion
✍ Scribed by Mugio Nishizawa; Arpita Yadav; Hiroshi Imagawa; Takumichi Sugihara
- Publisher
- Elsevier Science
- Year
- 2003
- Tongue
- French
- Weight
- 529 KB
- Volume
- 44
- Category
- Article
- ISSN
- 0040-4039
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✦ Synopsis
The first calculations of a C-ring model cation of sterol biosynthesis in the presence of selected counteranions have been performed. [TiCl 4 OH] -ion significantly stabilizes the perpendicular cation conformer that leads to carbon carbon bond migration and formation of a six-membered ring secondary cation. The [TiF 4 OH] -ion, however, stabilizes the parallel cation conformer that leads to hydride shift as observed indeed.