Access to the pactamycin core via an epoxide opening cascade

A synthetic strategy to establish five contiguous stereocenters, in a stereocontrolled manner, on the core structure of pactamycin is described. This sequence exploits the use of a Lewis acid mediated epoxide opening cascade to set the relative configuration of the C4–C5 diol while reversing the configuration at C7. This sequence provides the oxygenated core of pactamycin in just 11 steps.