Lodination, phenol

Indomethacin, 318 Insulin, in diabetes, 136 lodination of phenols, 97, 314 lodothiouracyl, 265 Iprindol, 318 Iproniazid, 254 Isoaminile, 82 Isobucaine, 12 Isocarboxazine, 233... 

In order to promote selective deprotonation at C-1 in 109, an electron attracting substituent is required at the para position, C-S. The nitrile group was chosen— also because it permitted ready conversion to phenolic hydroxyl at the end of the synthesis (Scheme 15). lodination of sulfone 109 followed by iodide-cyanide exchange gave the C-5 nitrile 115. The optically active acid (-f) 103 (Scheme 14), via its methyl ester (4-) 102, was converted in good yield into iodo olefin 116. 

Selective iodination of phenols, lodination of phenols with iodine results iiiiiinly in /xn-n-siibsliUilion iodination with thallium(l) acetate and iodine in wc( acetic acid or in melhylenc chloride results mainly in ort/io-substitution. 

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