| abstract |
Compounds of the formula 3806 כ" ח בשבט התשס" ב - February 10, 2002 wherein X is -O-, -S-, or -NR5-; R5 is C1-C3 alkyl, -COC6H5, -CO(C1-C6 alkyl), -SO2C6H5, or -SO2CF3; Y is -O-, -S-, -CH2-, -CH2CH2-, CH=CH- or -NR5-; each of R1a, R2a and R3a is independently -H, -O(C1-C4 alkyl), -Cl, -F, or a protected -OH; and Z is -OH, -OC6H5, -O(C1-C4 alkyl), or 4-hydroxyphenyl. |