The synthesis of (-)-1-(-3-amino-2-hydroxypropyl)thymine hydrochloride[(-)-(R)-(VIII)] by a catalytic hydrogenation of (-)-1-(3-
-azido-2-hydroxypropyl)thymine[(-)-(S)-(VII)] is described. The resolution of (2R)- and (2S)-(3j3-acetoxy-Ls-etienamidomethyl)-2,3\u27-
-dihydro-6-methyl-7H-oxazolo[3,2-a]pyrimidin-7-one[(2R)-(X) and
(2S)-(X)] by fractional crystallization, followed by the hydrolysis
of the resolved stereoisomers in 25% isopropanolic HCI afforded
the (+) and (-) amino-alcohol hydrochlorides VIlI, respectively,
The diastereoisomers X were prepared from (R,S)-2-aminomethyl-
2,3-dihydro-6-methyl-7H-oxazolo[3,2-a]pyrimidin-7-one (V)
and p-nitrophenyl 3j3-acetoxy-~5-etienate (XII) by the active ester
method. The conversion of X into VIlI proceeded via intramolecular
formation of (5R)- and (5S)-2-(313-acetoandrost-5-en-17-yl)-
-5-(thymin-1-yImethyl)oxazoline (XIII), accompanied by inversion
of configuration at the asymmetric C(2) centre. The purity of the
diastereoisomeric products X and XIII was determined by the
1H-NMR spectra
