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Stereoselective Synthesis of ( S )‐3,4‐Methylenedioxyamphetamines from ( R )‐Cyanohydrins
Author(s) -
Effenberger Franz,
Jäger Jürgen
Publication year - 1997
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.19970030825
Subject(s) - stereoselectivity , chemistry , reagent , catalytic hydrogenation , catalysis , aryl , organic chemistry , medicinal chemistry , alkyl
A stereoselective synthesis of ( S )‐3,4‐methylenedioxyamphetamines ( S )‐ 7 , which are highly interesting as psychoactive compounds, is described. Starting from readily available ( R )‐cyanohydrins ( R )‐ 2 the 2‐amino‐1‐aryl alcohols (1 R ,2 S )‐ 4 were obtained with high diastereoselectivity by addition of Grignard reagents to the O ‐protected cyanohydrins ( R )‐ 3 , transimination of the addition products A with primary amines, and hydrogenation of the imino intermediates B with NaBH 4 . For the hydrogenation of the benzylic hydroxyl group in the 1,2‐amino alcohols (1 R ,2 S )‐ 4 a new, very efficient method was developed. The optically pure amphetamines ( S )‐ 7 were obtained under very mild conditions by catalytic hydrogenation of the oxazolidinones (4 S ,5 R )‐ 6 , which were readily available by phosgenation of the amino alcohols (1 R ,2 S )‐ 4 .