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Optically Active 5-(Hydroxyalkyl)- and 5-(Aminoalkyl)pyrazolidin-3-ones by Ring-Chain Transformation of α,β-Unsaturated Lactones or Lactams with Hydrazines

✍ Scribed by Bohrisch, Jörg ;Faltz, Heike ;Pätzel, Michael ;Liebscher, Jürgen

Publisher
John Wiley and Sons
Year
1996
Tongue
English
Weight
513 KB
Volume
1996
Category
Article
ISSN
0947-3440

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✦ Synopsis

Abstract

α,β‐Unsaturated lactones or lactams 1 react with hydrazines 2 via Michael‐like addition and subsequent ring transformation by nucleophilic attack of the hitherto unchanged hydrazine nitrogen atom at the carbonyl carbon atom. The addition is highly trans‐stereoselective, thus affording optically active hydroxylalkyl‐ or aminoalkylpyrazolidin‐3‐ones 4 and 6. These pyrazolidin‐3‐ones are further transformed to tosylated, acetylated or silylated derivatives 9 or react with benzaldehyde to give the azomethine imine 10.

📜 SIMILAR VOLUMES

Synthesis of Chiral 4-(ω-Hydroxyalkyl)py
Synthesis of Chiral 4-(ω-Hydroxyalkyl)pyrazolidin-3-ones by Ring-Chain Transformation of α-Alkylidenelactones with Hydrazines
✍ Andreas Otto; Burkhard Ziemer; Jürgen Liebscher 📂 Article 📅 1998 🏛 John Wiley and Sons 🌐 English ⚖ 300 KB 👁 1 views

Enantiopure α-alkylidenelactones 7 were prepared by a Michael-like addition and ring-chain transformation affording optically active 4-(ω-hydroxyalkyl)pyrazolidin-3-Wittig reaction from α-bromolactones 4 and chiral aldehydes 6. Compounds 7 react with hydrazines 9 by stereoselective ones 11.

Synthesis of Chiral 4-(ω-Hydroxyalkyl)py
Synthesis of Chiral 4-(ω-Hydroxyalkyl)pyrazolidin-3-ones by Ring-Chain Transformation of α-Alkylidenelactones with Hydrazines
✍ Andreas Otto; Burkhard Ziemer; Jürgen Liebscher 📂 Article 📅 1999 🏛 John Wiley and Sons 🌐 English ⚖ 45 KB 👁 1 views

The configuration and/or formulae of the following compounds need to be corrected. (1ЈR,E)-3-(2-Benzyloxy-3-hydroxypropylidene)dihydrofuran-2-one (7c): Correct formula: (4S,5R,4ЈS)-5-(2,2-Dimethyl[1,3]dioxolan-4-yl)-4-(2-hydroxyethyl)pyrazolidin-3-one (11a): Original formula correct (4R,5S,1ЈR)-5-(1

ChemInform Abstract: Synthesis of Chiral
ChemInform Abstract: Synthesis of Chiral 4-(ω-Hydroxyalkyl)pyrazolidin-3-ones by Ring-Chain Transformation of α-Alkylidenelactones with Hydrazines.
✍ A. OTTO; B. ZIEMER; J. LIEBSCHER 📂 Article 📅 2010 🏛 John Wiley and Sons ⚖ 36 KB 👁 1 views

Synthesis of Chiral 4-(ω-Hydroxyalkyl)pyrazolidin-3-ones by Ring-Chain Transformation of α-Alkylidenelactones with Hydrazines. -This is the first access to optically active 4-(ω-hydroxyalkyl)pyrazolidin-3-ones. The lactone (IX), however, cannot be transformed into the corresponding pyrazolidinone.