Planar chiral systems, IV. An efficient route for the preparation of 5‐formyl‐4‐hydroxy[2.2]paracyclophane (FHPC)

Abstract

Abstract For the preparation of the title compound, 4 ‐hydroxy[2.2]paracyclophane ( 1 ) is first converted to the carbamate 2 . Metalation of 2 with sec ‐butyllithium yields an ortho ‐anion which after trapping with dimethylformamide and acidic work‐up provides 6 in 64% yield. Further application of the cyclophane anion include its capture by trimethylsilyl chloride to the trimethylsilyl derivative 3 (76%) and its Fries rearrangement to the phenol 4 (78%). The spectroscopic and analytical data of the new compounds are described in full detail.