Total Synthesis of Anhydroryanodol and Formal Synthesis of Ryanodol and Ryanodine

Building on our prior synthesis of the representative Ryanodane diterpene garajonone, we report here the chemical synthesis of anhydroryanodol, a significant degradation product of Ryanodane diterpenes that features distinct oxidation sites, utilizing the same advanced intermediate. This was accomplished through a series of late-stage regio- and stereoselective redox operations. This study, in conjunction with our earlier synthesis of garajonone, represents the first unified approach to the synthesis of Ryanodane diterpenes with differing oxidation sites based on a single synthetic strategy.