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Stereoselective Synthesis of (S)-3,4-Methylenedioxyamphetamines from (R)-Cyanohydrins

✍ Scribed by Prof. Dr. Franz Effenberger; Dr. Jürgen Jäger

Publisher
John Wiley and Sons
Year
1997
Tongue
English
Weight
631 KB
Volume
3
Category
Article
ISSN
0947-6539

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✦ Synopsis

Abstract

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.

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