Abstract
The first total synthesis of (±) -sanadaol, structurally unique marine diterpene isolated from brown algae Pachydictyon coriaceum and Dictyota crenulata, is described. The key step of this fully stereocontrolled synthesis involves the fragmentation reaction of tricyclic compound 21 forming bicyclic compound 22 having suitably functionalised framework of sanadaol. Further, both (-) - and (+) -sanadaol were synthesized stereoselectively from D-mannitol via chiral bicyclo [2.2.2] octane derivative 47. This accomplishment determined the absolute configuration of sanadaol and that of dictyodial as shown in (+) -1 and 59, respectively.
