Chalcane-containing dimers are major compounds identified
from
dragon’s blood, the red resin that accumulates in Dracaena trees after injury. The key step for the formation of these dimers
was a p-quinone methide (p-QM, 3) mediated nonenzymatic Michael addition. Compound 3 is derived from the spontaneous dehydration of chalcane
alcohol-M274 (2). Two dihydroflavonol-4-reductases, discovered
in D. cambodiana, reduce dihydrochalcone-M272 (7) to 2. Moreover, the application potential
of p-QMs was demonstrated using a 3-like p-QM to synthesize diverse dimeric derivatives.