9-Fluorenol preparation

Methylfluorene has been prepared by cleavage of ethyl 9-methyl-9-fluorenylglyoxylate,4 by the decarboxylation of 9-methylfluorene-9-carboxylic acid,4 by the decarboxylation of 9-fluorenylacetic acid,6 by the cleavage of 9-methyl-9-acetyl-fluorene with alcoholic potassium hydroxide or soda-lime,6 by the reduction of 9-methyl-9-fluorenol with hydriodic acid in acetic acid,7 by the reaction of 9-fluorenyllithium 8 or -sodium 9 with methyl iodide or methyl sulfate,9 by the cyclization of diphenylmethyl carbinol over platinum-on-carbon at 300°,10 by the reaction of ethyl 9-methoxymcthyl-9-fluorcnylcarboxylate,11 by the diazotization and heating of 2-ethyl-2-aminobiphenyl,12 by the dehydration and then reduction of 9-mcthyl-9-fluorcnol,13... 

Hypochlorites are very good oxidizers of alcohols and are frequently selective enough to oxidize secondary alcohols in preference to primary alcohols see equations 288-291). Solutions of sodium hypochlorite in acetic acid react exothermically with secondary alcohols within minutes [693]. Calcium hypochlorite in the presence of an ion exchanger (IRA 900) oxidizes secondary alcohols at room temperature in yields of 60-98% [76 5]. Tetrabutylammonium hypochlorite, prepared in situ from 10% aqueous sodium hypochlorite and a 5% dichloromethane solution of tetrabutylammonium bisulfate, oxidizes 9-fluorenol to fluorenone in 92% yield and benzhydrol to benzophenone in 82% yield at room temperature in 35 and 150 min, respectively [692]. Cyclohexanol is oxidized to cyclohexanone by teit-butyl hypochlorite in carbon tetrachloride in the presence of pyridine. The exothermic reaction must be carried out with due precautions [709]. 

Fluorenol has been prepared in 60% yield by the photolysis during 12 hours of a dilute mixture of benzophenone and propanone oxime in methanol in a double-walled, internally-cooled pyrex tube (ref.24). 

Similarly, perchloro-9-phenylfluorene does not give fluorenol [37] (steric hindrance) but rather a mixture of ketones [35] and [36] instead (Ballester et al., 1983b). Pathway (23) is presumably followed, since the hydrolysis of carbenium ion [34] hexachloroantimonate, prepared independently, yields the same mixture of ketones. In Section 9, the preparation and isolation (as salts) of closely related perchloroarylcarbenium ions is described. 

Work with a partner on this part of the experiment. Prepare two thin-layer plates in the same way as you did in Experiment 6A, except that one plate should be 10 cm X 5.3 cm and the other one, 10 cm x 4.3 cm. When you mark them with a pencil for spotting, make five marks 1 cm apart on the first plate and four marks on the second plate. During the reaction, you will be taking five samples from the reaction mixture at 0,15,30,60, and 120 seconds. Three of these samples should be spotted on the larger plate and two of them on the smaller one. In addition, each plate should be spotted with two reference solutions, one containing fluorenone and the other fluorenol. Using a pencil to make very light marks, indicate at the top of each plate where each sample will be spotted so that you can keep track of them. Write the number of seconds and an abbreviation for the two reference compounds. Use the same TLC development chamber with methylene chloride that you used in Experiment 5A. Prepare seven micropipettes to spot the plates. 

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