The total synthesis of (+)-ryanodol. Part IV. Preparation of (+)-ryanodol from (+)-anhydroryanodol

This paper reports the transformation of (+)-anhydroryanodol (6) to (+)-ryanodol (7) by reductive cyclization of lactone epoxide derivatives 9 and 20 (Scheme 4). Keywords: anhydroryanodol, ryanodol, diterpene, synthesis, reductive cyclization.