Order of Synthesis Steps to Avoid Protecting Groups

The same intermediate 13 has been also synthesized recently featuring the late introduction of the second hydroxyl group. This obviated the necessity to differentiate 

HO PMBCI PMBO (COCI)2, DMSO PMBO (EtOhPOCHjCOaEt OH 

Another synthesis of asteriscanolide was completed at about the same time [35], this time introducing oxygen functionality early and during the assembly of the 

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