✦ LIBER ✦

Enantioselective Generation and Diastereoselective Reactions of Chiral Enolates Derived from α-Heterosubstituted Carboxylic Acids. Preliminary Communication

✍ Scribed by Dieter Seebach; Reto Naef

Publisher: John Wiley and Sons
Year: 1981
Tongue: German
Weight: 269 KB
Volume: 64
Category: Article
ISSN: 0018-019X
DOI: 10.1002/hlca.19810640829

No coin nor oath required. For personal study only.

✦ Synopsis

Abstract

Dioxolanones 7 and 8a and oxazolinones 9a derived from pivalaldehyde and lactic acid, mandelic acid, and proline, respectively, furnish chiral enolates of type 3 by deprotonation with LDA. Reactions of these enolates with alkyl halides, aldehydes, and ketones (→ 8b, 9b, 11–13) are highly diastereoselective. Thus, the overall enantioselective α‐alkylation of chiral, non‐racemic α‐heterosubstituted carboxylic acids (4 → 6) is realized.

📜 SIMILAR VOLUMES

Catalytic, Enantioselective [4 + 2]-Cycl

Catalytic, Enantioselective [4 + 2]-Cycloadditions of Ketene Enolates and o-Quinones: Efficient Entry to Chiral, α-Oxygenated Carboxylic Acid Derivatives.

✍ Tefsit Bekele; Meha H. Shah; Jamison Wolfer; Ciby J. Abraham; Anthony Weatherwax 📂 Article 📅 2006 🏛 John Wiley and Sons ⚖ 27 KB 👁 1 views

1,3-Dioxanone Derivatives from β-Hydroxy

1,3-Dioxanone Derivatives from β-Hydroxy-carboxylic Acids and Pivalaldehyde. Versatile Building Blocks for Syntheses of Enantiomerically Pure Compounds. A Chiral Acetoacetic Acid Derivative Preliminary Communication

✍ Dieter Seebach; Jürg Zimmermann 📂 Article 📅 1986 🏛 John Wiley and Sons 🌐 German ⚖ 346 KB

9.VI. 86) (R)-3-Hydroxybutyric acid (from the biopolymer PHB) and pivalaldehyde give the crystalline cis-or (R, R)-2-(tert-butyl)-6-methy1-1,3-dioxan-4-one (la), the enolate of which is stable at low temperature in THF solution and can be alkylated diastereoselectively (-3, 4, 5, and 7). Phenylselen

ChemInform Abstract: Asymmetric Brominat

ChemInform Abstract: Asymmetric Bromination—Aldolization of Chiral Acetate Titanium Enolate Derived from Thioimide. A General Approach to the Synthesis of Enantiopure α-Bromo-β-hydroxy Carboxylic Acids.

✍ Ying-Chuan Wang; Dah-Wei Su; Chen-Men Lin; Hsi-Liang Tseng; Chi-Lung Li; Tu-Hsin 📂 Article 📅 2010 🏛 John Wiley and Sons ⚖ 31 KB 👁 2 views

Studies on the Generation of Enolate Ani

Studies on the Generation of Enolate Anions from Butane-2,3-diacetal Protected Glycolic Acid Derivatives and Subsequent Highly Diastereoselective Coupling Reactions with Aldehydes and Acid Chlorides.

✍ Steven V. Ley; Darren J. Dixon; Richard T. Guy; Maria A. Palomero; Alessandra Po 📂 Article 📅 2005 🏛 John Wiley and Sons ⚖ 59 KB 👁 2 views

Enantioselective Synthesis of β-Amino Ac

Enantioselective Synthesis of β-Amino Acids. Part 13. Diastereoselective Alkylation of Dianions Derived from Chiral Analogues of β-Aminopropanoic Acid Containing the α-Phenylethyl Group.

✍ Victor Manuel Gutierrez-Garcia; Gloria Reyes-Rangel; Omar Munoz-Muniz; Eusebio J 📂 Article 📅 2003 🏛 John Wiley and Sons ⚖ 149 KB 👁 1 views

Enantioselective Synthesis of β-Amino Ac

Enantioselective Synthesis of β-Amino Acids, Part 13 : Diastereoselective Alkylation of Dianions Derived from Chiral Analogs of β-Aminopropanoic Acid Containing the α-Phenylethyl Group

✍ Víctor Manuel Gutiérrez-García; Gloria Reyes-Rangel; Omar Muñoz-Muñiz; Eusebio J 📂 Article 📅 2002 🏛 John Wiley and Sons 🌐 German ⚖ 129 KB

## Abstract Inexpensive acryloyl chloride was converted in 91% overall yield to two derivatives of __β__‐alanine, (__R__,__R__,__R__)‐**6** and (__R__,__R__,__S__)‐**6**, containing two chiral auxiliaries. __C__‐Alkylation of (__R__,__R__,__R__)‐ and (__R__,__R__,__S__)‐**6** __via__ a dianion deri