Starting material oriented strategy

When the methodology of stereoselective synthesis was still in its infancy, it was considered advantageous to utilize sequences of stereogenic centers available from enantiomerically pure natural products as building blocks [3, 4] this so-called chiral pool synthesis strategy is exemplified in Scheme 4.2. The bicyclic acetal structure of exo-brevicomin (31) can be ret-rosynthetically linked to the chiral ketodiol 32, which can be derived from (S,S)-(-)-tartaric acid, a readily available chiral starting material. This leads to the building block oriented bond-set depicted in intermediate 32. 

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