Axially chiral hemiaminals from nonracemic α-amino acid derivatives (thiohydantoins): Synthesis and isomer identification.

Autor: Sarigul Ozbek S; Faculty of Pharmacy, Acıbadem Mehmet Ali Aydınlar University, İstanbul, Turkey., Dogan I; Department of Chemistry, Boğziçi University, İstanbul, Turkey.
Jazyk: angličtina
Zdroj: Chirality [Chirality] 2020 Nov; Vol. 32 (11), pp. 1299-1310. Date of Electronic Publication: 2020 Aug 07.
DOI: 10.1002/chir.23274
Abstrakt: Stable, nonracemic axially chiral hemiaminals (O,N-hemiacetals) have been synthesized stereoselectively from lithium aluminum hydride (LiAlH 4 ) reductions of nonracemic 5-methyl- and 5-isopropyl-3-(o-aryl)-2-thioydantoins in tetrahydrofuran (THF) at room temperature in 10 min. Predominantly S-configured hemiaminals at C-4 of the heterocyclic ring were produced from the S-configured thiohydantoins at C-5 (by 80% when the C5 substituent is methyl and by 97% when it is isopropyl). The configuration at C-5 was retained during the reduction reaction. The stereochemical outcome of the axially chiral hemiaminals resulted from their conformational preferences.
(© 2020 Wiley Periodicals LLC.)
Databáze: MEDLINE
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