Integramycin

Electrophilic spirocyclization may also be performed on hemiacetals. This method has been used most recently by Roush et al. [124] in the synthesis of a model spiroacetal fragment toward integramycin (Scheme 55). Thus, a 1 1.3 mixture of ketone 231 and hemiacetal 232 was treated with NIS in dichloromethane to... 

Scheme 55 Roush et al. s synthesis of integramycin model spiroacetal 233 [124]...

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