Pretazettine (1), which shows antileukemic activity, was obtained by conversion of tazettine (2) to 3-epitazettadiol (3) [whose structure was confirmed by its cyclization to deoxypretazettine (4)], followed by manganese dioxide oxidation of 3. The transformation of 2 to 1 confirmed the stereochemistry of pretazettine (1).
Total synthesis of dl-tazettine and 6a-epipretazettine: a formal synthesis of dl-pretazettine. Some observations on the relationship of 6a-epipretazettine and tazettine