Efficient generation of a trisporoid library by combination of synthesis and biotransformation

Trisporic acids and their biosynthetic precursors represent a family of powerful fungal pheromones and morphogenetic factors. A highly flexible synthetic protocol is described that (i) provides rapid access to nonfunctionalized early trisporoids from beta-ionone, (ii) includes a regiospecific oxidative functionalization of beta-ionone leading to 1-acetoxy-beta-ionone giving access to functionalized trisporoids, and (iii) utilizes a biotransformation of early synthetic trisporoids by growing cells of Blakeslea trispora to prepare late trisporoids including trisporic acids. The same protocol also provides deuterium-labeled trisporoids such as trisporin B [2H3]-19. Administration of [2H3]-19 to growing cells of the (-)-mating type of B. trispora resulted in the formation of the labeled trisporols [2H3]-20 and [2H3]-21. Growing cultures containing both mating types can be used to prepare trisporic acids from early precursors.