Novel cap analogs which are easily synthesized, resulting in high levels of capping efficiency and transcription and improved translation efficiencies are provided. Such caps are methylated at the N7 position of one or both guanosines of the dinucleotide cap as well as at the 3' position on the ribose ring. Substituent groups on the ribose ring also result in the cap being incorporated in the forward orientation. Also provided are methods useful for preparing capped analogs and using mRNA species containing such analogs are also contemplated herein, as well as kits containing the novel cap analogs.
