3/3 Acetoxy-18 iodo-5 pregnene

Acetoxy-18-iodo-18,20/3-oxido-5-pregnene, oxidation to 18,20-lactone, 46, 57... 

B. 3 -Acetoxy-18-iodo- and 18-hydroxy-18,20 -oxido-5-pregnene. In a 5-1. three-necked flask fitted with a mechanical stirrer, a thermometer, and a reflux condenser are placed 31. of cyclohexane (Note 6), 180 g. ca. 0.37 mole) of commercial lead tetraacetate containing approximately 10% acetic acid (Note 7), 24 g. (0.095 mole) of iodine and 30 g. (0.083 mole) of 3j3-acetoxy-20j8-hydroxy-5-pregnene. The reaction mixture is stirred and heated to the boiling point by irradiation with a 1000-watt lamp (Note 8) from underneath. When the iodine color has disappeared (usually after about 60-90 minutes) (Note 9), the reaction mixture is cooled to room temperature, filtered with suction, and the... 

A soln. of 3y ,17a-dihydroxy-5-pregnene-12,20-dione in tetrahydrofuran-metha-nol treated with powdered GaO and a little azodiisobutyronitrile as initiator, then a soln. of iodine in tetrahydrofuran-methanol added dropwise at a rate just exceeding the rapid decolorization, the resulting crude 21-iodo derivative dissolved in acetone, mixed with acetic acid and triethylamine, then refluxed 45 min. -> 21-acetoxy-3), 17a-dihydroxy-5-pregnene-12,20-dione. Y 66%.— Even... 

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