A highly diastereoselective total synthesis of TBDPS-protected (–)-cryptocaryolone
has been achieved in 12 linear steps with an overall yield of 7.1%, following a recently
developed Prins cyclization strategy for the construction of trans-2,6-disubstituted 3,4-dihydropyrans. Another key intermediate, i.e. syn-1,3-diol, was prepared by the Wacker oxidation followed by a hydroxyl-directed syn-reduction of the keto functionality. In this report, the versatility of Prins cyclization
in the total synthesis of TBDPS-protected (–)-cryptocaryolone is demonstrated. The
key steps involved in the approach are Prins cyclization for the construction of the
trans-2,6-disubstituted dihydropyran, Wacker oxidation and a hydroxyl-directed syn-reduction reaction.
Key words
Prins cyclization - Wacker oxidation - hydroxyl-directed
syn-reduction - cryptocaryolone - bicyclic lactones
