(R)-N-(β-Trichlorogermyl propionyl)thiazolidine-2-thione-4- carboxylic methyl ether 1 [α]~D^2^0-89.40° was prepared by the reaction of trichlorogermyl propionyl chloride with (R)- thiazolidine-2-thione-4-carboxylic methyl ether. The (R)-(β- substituted propionyl thiazolidine-2-thione-4-methoxycarbonyl) germanium sesquioxide 2 was obtained by hydrolysis of compound 1, [α]~D^2^0-49.29°. The crystal structure of the title compound was determined by X-ray diffraction method. It is orthorhombic system with a=0.6192(1)nm, b=1.1147(4)nm, c=2.1796(8)nm, V=1.5045nm^3, Z=4, space group P2~12~12~1. The C=O group and C=S group are located in the opposite sides of C(4)-N-C(3) bonds, with trans-configuration in the molecule. The electronic structure of the title compound was studied by MNDO molecular orbital method. Distribution of the calculated net charges and bond orders were obtained. Nature of the frontier orbital transition and electronic spectra was discussed.

Key words: SYNTHESIS, THIAZOLE P, THIOKETONE, CRYSTAL STRUCTURE, X-RAY DIFFRACTION ANALYSIS, UNIT CELL, CARBOXYLIC ACID ESTER, PARAMETER, ELECTRONIC STRUCTURE, MOLECULAR ORBITAL METHOD