CONDENSATION REACTION OF BETA-TRIPHENYLGERMANYL PROPIONIC-ACID WITH ALPHA-HYDROXY PHOSPHONIC ESTER AND THE STRUCTURE OF THE PRODUCTS

The sterically hindered condensation of beta-triphenylgermanyl propion ic acid with alpha-hydroxy phosphonic ester has been studied. The fail ure of conventional ways of the condensation is probably dde to the bu lky groups Ph(3)Ge- and -P(O)(OR)(2), However, several novel O,O-dialk yl-alpha-(beta-triphenylgermanyl) propionoxy phosphonic esters have be en synthesized sucessfully in good yields by using DCC catalyzed by py ridine or HOBt. The reactivity has much to do with the steric hindranc e of the groups R. The larger the OR, the slower the reaction rate is. All the new products were characterized by H-1 NMR, IR spectra, MS an d elemental analyses. A single crystal A(1) was obtained and the struc ture was determined by X-ray diffraction. Preliminary bioassays showed that the new products exhibit antitumor activity.