The Chiral Glycine Enolate Derivative from 1-Benzoyl-2-(tert-butyl)-3-methyl-1,3-imidazolidin-4-one is Alkylated in the 5-Position with Relative Topicity lk. Preliminary Communication
✍ Scribed by Dieter Seebach; David D. Miller; Stefan Müller; Theodor Weber
- Publisher
- John Wiley and Sons
- Year
- 1985
- Tongue
- German
- Weight
- 252 KB
- Volume
- 68
- Category
- Article
- ISSN
- 0018-019X
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✦ Synopsis
Abstract
An overall enantioselective substitution of the R‐group of an α‐hydroxy‐ or α‐amino acid 1 [RCH(XH)COOH] by another R‐group is possible through heterocycles 2 obtained from 1 with pivaladehyde (1 → 7). The rac‐ and the (S)‐(+)‐heterocycles 8 (title compounds of type 5) are prepared from glycine and O‐benzyl‐(S)‐serine, respectively. Their enolates (cf. 9, type 6) are alkylated with iodomethane, iodobutane, 2‐iodopropane, benzyl bromide, and acetone to give the trans‐disubstituted imidazolidinones 10 with ≥ 95% diastereoselectivity. The configuration of the products is established by chemical correlation with alanine, phenylalanine, and valine.