Total Synthesis of (+)-Aplykurodinone-1.

Starting from (R)-citronellic acid and (R)-seudenol, the total synthesis of (+)-aplykurodinone-1, a highly degraded marine steroid, has been achieved in 11 steps and in 19% overall yield with excellent stereochemical control. In addition to the features such as an Ireland-Claisen rearrangement, an intramolecular carbonyl-ene cyclization, and an intramolecular Michael addition, the present synthetic strategy is accomplished without the use of protecting groups.