Halohydrins, Amino Hydroxy Compounds, and Esters

Conversion into Halohydrins, Amino Hydroxy Compounds, and Esters 

The addition of halogens and hydroxyls across double bonds leads to halohydrins, which are useful intermediates, especially for the synthesis of epoxides. Such additions are achieved by treatment of alkenes with N-bromoacetamide [1104] or iV-brontosuccinintide [746] in aqueous media and give products of anti addition. On heating with alkalies, bromohydrins 

Vicinal amino hydroxy compounds are prepared by treatment of al-kenes with V-chloroamides in the presence of osmium tetroxide (equation 87) [72J, 1105]. 

Heating alkenes and cycloalkenes with manganese triacetate yields lactones resulting from an oxidative addition of acetoxyls across the double bonds (equation 88) [50J]. 

Acyl esters of vicinal diols are obtained by the reaction of alkenes with metal carboxylates [436]. Lead tetraacetate in acetic acid at 70 °C converts 1,2-dihydronaphthalene to rranj-l,2-diacetoxy-l,2,3,4-tetrahy-dronaphthalene in 72% yield [436]. The reaction is not always stereospecific. Cyclohexene treated with thallium triacetate gives a mixture of diastereomers in varying ratios, depending on reaction conditions, and byproducts as a result of rearrangements (equation 89) [411], 

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