PLANAR CHIRAL SYSTEMS .4. AN EFFICIENT ROUTE FOR THE PREPARATION OF 5-FORMYL-4-HYDROXY[2.2]PARACYCLOPHANE (FHPC)

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.