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Nucleophile Ringöffnung von 1-Nitro-1-cyclopropancarbonsäure-arylestern mit sterisch geschützter, aber elektronisch wirksamer Carbonyl- und Nitrogruppe. Ein neues Prinzip der Aminosäuresynthese

✍ Scribed by Vettiger, Thomas ;Seebach, Dieter


Book ID
102902254
Publisher
John Wiley and Sons
Year
1990
Tongue
English
Weight
761 KB
Volume
1990
Category
Article
ISSN
0947-3440

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✦ Synopsis


Nucleophilic Ring Opening of Aryl 1‐Nitro‐1‐cyclopropanecarboxylate with Sterically Protected, but Electronically Effective Carbonyl and Nitro Group. A New Principle of Amino Acid Synthesis

The readily available [2,6‐di‐(tert‐butyl)‐4‐methoxyphenyl] 1‐nitro‐1‐cyclopropanecarboxylate (4) is ring‐opened by nucleophilic attack of the amino groups of (S)‐α‐amino acid esters (products 20–26). Reduction of the nitro group gives rise to derivatives 27–30 of 2,4‐diaminobutanoic acid which are connected with a second amino acid through the nitrogen in position 4 (2‐substituted 6‐amino‐3‐azaheptanedioic acids). In two cases, these were converted into enantiomerically and diastereomerically pure Freidinger's γ‐lactam dipeptides (31, 32), which have previously been shown to mimic a peptide β‐turn.


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Nucleophile Ringöffnung von α-Nitrocyclo
✍ Dieter Seebach; Robert Häner; Thomas Vettiger 📂 Article 📅 1987 🏛 John Wiley and Sons 🌐 German ⚖ 660 KB

The readily available 2,4,6-tri(terf-buty1)-and 2,6-di(tert-butyl)-4-methoxyphenol esters 2 of a-nitrocyclopropanecarboxylic acid undergo ring opening with C-, N-, 0-, and S-nucleophiles (cyanide, malonate, azide, anilines, alkoxides, phenoxides, thiolates) in DMF or alcohol solvents (80-95 % yield)