Total synthesis of (±)-6-deoxycastanospermine: an application of the addition of organoboronates to N-acyliminium ions

An efficient synthesis of (±)-6-deoxycastanospermine is reported, using a diastereoselective coupling of organoboronates with N-acyliminium ions as the key step. The construction of the indolizidine ring system is completed using a subsequent reductive amination reaction.