4-Chlorophenol (8) reacted with acryloyl chloride in the presence of Et_3N as acid scavenger to give acrylic acid 4-chlorophenyl ester (7). Compound 7 was heated at 155~°C with A1C1_3 to undergo Fries rearrangement and ring closure affording 4-chloro-7-hydroxy-indan-l- one (6) . Reduction of the carbonyl group of 6 with NaBH_4/CH_3OH or LiAlH_4/THF gave 4-chloro-indan-l,7-diol (5). Two unexpected ethers (methyl etherified product 9 and dimerized ether 10) were formed in this reduction if the workup procedure is not controlled carefully. The structure of 9 was determined by X-ray diffraction analysis and the mechanism of etherification was proposed. 1-Hydroxy group of 5 is easy to form its ether derivative 10 through an intramolecular catalysis of carbon cation formation, followed by the reaction with compound 5 itself. Therefore, the workup of the reaction mixture and separation of product 5 should be done as soon as possible after the reduction was completed in order to prevent the formation of ether byproducts. New compounds 5, 9 and 10 were characterized by ~1H NMR, ~13C NMR, MS and elemental analysis or HRMS.

Key words: INDENE P;ETHERIFICATION;PHENOL P;ACYL CHLORIDES;PROPENOIC ACID ESTER, XRD