Alkylierung in der 2-Stellung von (2S, 4R)- 4-Hydroxyprolin unter Retention
✍ Scribed by Theodor Weber; Dieter Seebach
- Book ID
- 102254133
- Publisher
- John Wiley and Sons
- Year
- 1985
- Tongue
- German
- Weight
- 457 KB
- Volume
- 68
- Category
- Article
- ISSN
- 0018-019X
No coin nor oath required. For personal study only.
✦ Synopsis
Alkylation in the 2‐Position of (2__S__, 4__R__)‐4‐Hydroxyproline with Retention of Configuration
O‐Acetyl‐4‐hydroxyproline (1b) is condensed with pivalaldehyde to give a single stereoisomer of the 2‐(tert‐butyl)‐4‐oxo‐3‐oxa‐1‐azabicyclo[3.3.0]oct‐7‐yl acetate (3). This is converted to the enolates 4 or 5, reactions of which with alkyl halides, aldehydes, and acetone (→6,9,10,11) are diastereoselective (lk‐1,3‐induction). Cleavage of the corresponding products furnishes the enantiomerically pure 2‐deuterio‐, 2‐methyl‐, 2‐allyl‐, and 2‐benzyl‐substituted 4‐hydroxyprolines 2a–2d.
📜 SIMILAR VOLUMES
ZUSCHRIFTEN [12] Fur 5 a und 5 b wurden ausschlieDlich irreversible Elektronentransferreaktionen elektrochemisch festgestellt: heispielsweise fur 5 a an Glaskohlenstoff-Elektrode in 1,2-Dimethoxyethdn mil (nBu),NPF, als Leitelektrolyt bei ED(oxl = + 0.86 V und