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Asymmetric syntheses via heterocyclic intermediates, XL. Studies on the acylation of lithiated bislactim ethers of cyclo(-L-Val-Ala-) and cyclo(-L-Val-Gly-) Asymmetric synthesis of (R)-α-alkenyl and (R)-α-ethinyl alanine methyl esters by the bislactim ether method

✍ Scribed by Schöllkopf, Ulrich ;Westphalen, Karl-Otto ;Schröder, Jürgen ;Horn, Klaus

Publisher: John Wiley and Sons
Year: 1988
Tongue: English
Weight: 678 KB
Volume: 1988
Category: Article
ISSN: 0947-3440
DOI: 10.1002/jlac.198819880813

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✦ Synopsis

must be larger than 97.5:2.5 (d.e. > 95O/0). With acetyl chloride (3a) the N-acylated isomer 7 is formed as a byproduct.

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Asymmetric Synthesis via Heterocyclic in

Asymmetric Synthesis via Heterocyclic intermediates, L. – Trichloroacetimidates, II. Asymmetric Synthesis of α-Amino Acid Benzyl Esters via the Bisbenzyl Bislactim Ether of cyclo(-L-Val-Gly-)

✍ Groth, Ulrich ;Schmeck, Carsten ;Schöllkopf, Ulrich 📂 Article 📅 1993 🏛 John Wiley and Sons 🌐 English ⚖ 322 KB 👁 1 views

## Abstract The diketopiperazine cyclo(‐L‐Val‐Gly‐) (1) can be __O__‐alkylated under mild acidic reaction conditions with the alkyl trichloroacetimidates 2 to the corresponding bisalkyl bislactim ethers. Alkylation of the bisbenzyl bislactim ether anion of cyclo(‐L‐Val‐Gly‐) 4c with benzyl bromide