First Enantiospecific Synthesis of Marine nor‐Sesquiterpene (+)‐Austrodoral from (‐)‐Sclareol.

Abstract A short and efficient synthesis of the rearranged nor-sesquiterpenes (+)-austrodoral ( 1 ) and (+)-austrodoric acid ( 2 ), recently isolated from the Antarctic marine mollusk Austrodoris kerguelenensis , from diterpene (−)-sclareol ( 4 ) is reported. The key step of the sequence is the pinacol rearrangement of the drimanetriol 11 .