Compounds of Formula I:and compounds of Formula II:are provided. Pharmaceutical compositions comprising either the compound of Formula I or Formula II are disclosed. Methods of treating patients having cancer are provided by administering to the patient a therapeutically effective amount of one or more compounds having Formula I or Formula II to treat the patient. The compounds of Formula I or II are preferably conformationally restricted furo[2,3-d]pyrimidines having dual inhibition of microtubule assembly and receptor tyrosine kinases.