SYNTHESIS AND CONFORMATIONAL-ANALYSIS OF 3-AMINO-2-DECALONES

A diastereoisomeric mixture of three 3-Z-amino-2-decalones (Z = benzyl oxycarbonyl or carbobenzoxy) synthesized from 3-Boc-amino-1,2,3,4-tetr ahydro-2-naphthalenol (Boc = teut-butyloxycarbonyl) was resolved by hi ghperformance liquid chromatography on silica gel, For each isomer, th e relative stereochemistry of chiral carbons and the conformation were assessed by H-1 and C-13 NMR, In the three isomers, the Z-amino group adopts an equatorial orientation, Inversion of configuration of the a lpha-amino chiral carbon induces a double chair inversion when the rin g junction is cis, in order to keep the Z-amino group equatorial.