##STR1## wherein R, R', R.sub.1, and R.sub.1 ', which are the same or different, are H, C.sub.1 -C.sub.4 alkyl, linear or branched C.sub.1 -C.sub.4 mono- or polyhydroxyalkyl; R.sub.2, R.sub.2 ', R.sub.3, and R.sub.3 ', which are the same or different, are one of the groups of formula --CH.sub.2 CH.sub.2 OH, --CH.sub.2 CH(OH) CH.sub.2 OH --CH(CH.sub.2 OH)CH(OH)CH.sub.2 OH, --CH.sub.2 (CHOH).sub.4 CH.sub.2 OH, or --CH(CH.sub.2 OH).sub.2 ; and X is one of the groups --CH(OH)--, --CH(CH.sub.2 OH)--, --C(OH) (CH.sub.2 OH)--, or --C(CH.sub.2 OH).sub.2 --, are useful as opacifying components for X-ray contrast media.
其中R,R',R1和R1',它们相同或不同,是H,C1-C4烷基,线性或支链C1-C4单或多羟基烷基;R2,R2',R3和R3',它们相同或不同,是以下公式组之一的基团- OH,- CH(OH) OH,-CH( OH)CH(OH) OH,-
CH2(CHOH)4 OH,或-CH( OH)2;而X是以下组之一-CH(OH)-,-CH( OH)-,-C(OH)( OH)-,或-C( OH)2-,对于X射线造影剂的浑浊成分是有用的。