The present invention provides processes and synthetic intermediates for the synthesis of 4-substituted ((1 S , 2 S , 4 R )-2-hydroxy-4-{7H-pyrrolo[2,3-d]pyrimidin-7-yl}cyclopentyl)methyl sulfamates, which are E1 activating enzyme inhibitors, and are useful for the treatment of disorders of cell proliferation, particularly cancer, and other disorders associated with E1 activity.