Anti 1,2-dihydroxylation, of alkenes

We can carry out anti 1,2-dihydroxylation of a double bond by converting the alkene to an epoxide and then carrying out an acid-catalyzed hydrolysis (Section 11.15). 

Anti 1,2-dihydroxylation (Section 11.15) The installation of hydroxyl groups at adjacent carbons and on opposite faces of an alkene, often accomplished by ring-opening of an epoxide. 

The AD reaction was central in the preparation of (+)-cw-sylvaticin 41,27 a natural product found to have potent anti-tumor activity. The ability of this compound to inhibit ATP production by blockade of the mitochondrial complex I was thought to be the origin of this biological outcome. The AD reaction, in this example, exploited the preference of this reaction for the oxidation of 1,2-frans-alkenes over monosubstituted alkenes. The E,E-isomer of tetradecatetraene 42 could be chemoselectively dihydroxylated at both internal alkenes, while the terminal alkenes remained untouched. Thus, 43 was generated in excellent chemical yield. 

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