Reaction of malonates with camphoranile synthesis of 4‐hydroxy‐2‐pyridones attached to the bornane ring system

The reaction of camphoraniles 3a,b with “magic malonates” (bis‐2,4,6‐trichlorophenylmalonates) 4a,b leads to 4‐hydroxy‐2(1 H )‐pyridones attached to bornane ring system 6a‐c in good yields. Less satisfactory yields were obtained with the diethyl malonate 5b . The reaction of an excess of diethyl malonate 5 itself with 3b yields the pyrono derivative 7 , which can readily be degraded via the acetyl derivative 8 to the basic structure 9 .