There are provided methods and systems to form propylene chlorohydrin by hydrolysis of dichloropropane in presence of Lewis acid and to further form propylene oxide from the propylene chlorohydrin.

There are provided methods and systems to form propylene chlorohydrin by hydrolysis of dichloropropane in presence of Lewis acid and to further form propylene oxide from the propylene chlorohydrin.

A method for preparing a partially fluorinated alcohol. comprises reacting an epoxide: wherrein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are independently selected from the group comprising H, F, Cl, Br, I, CF.sub.3, alkyl, fluoroalkyl, haloalkyl with a fluorinating agent.

##STR00001##

A method for preparing a partially fluorinated alcohol. comprises reacting an epoxide: wherrein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are independently selected from the group comprising H, F, Cl, Br, I, CF.sub.3, alkyl, fluoroalkyl, haloalkyl with a fluorinating agent.

##STR00001##

Disclosed herein are borazine complexes and use of the same in perfluoroalkylation reactions.

Provided is a method for preparing an epoxide by halohydrination, the method comprising: (1) halohydrination: adding H.sub.2O, a halogen(s) and an olefin compound to a reaction device for reaction to obtain a halohydrin; (2) saponification: saponificating the halohydrin with an alkali metal hydroxide to obtain an epoxide and an alkali metal halide; (3) performing a bipolar membrane electrodialysis of the alkali metal halide to obtain an alkali metal hydroxide and a halogen hydride. Also provided is a method for preparing an epoxide by halohydrination, the method comprising: (1) halohydrination: halohydrinating a halogen hydride, an H.sub.2O.sub.2 and an olefin compound to obtain a halohydrin; optionally, (2) saponification: saponificating the halohydrin with an alkali metal hydroxide to obtain an epoxide and an alkali metal halide; optionally, (3) performing a bipolar membrane electrodialysis of the alkali metal halide to obtain an alkali metal hydroxide and a halogen hydride. The method according to the present invention can prepare a halohydrin or an epoxide at very high selectivity and yield, and greatly reduce the amount of waste water and waste slag discharges.

Provided is a method for preparing an epoxide by halohydrination, the method comprising: (1) halohydrination: adding H.sub.2O, a halogen(s) and an olefin compound to a reaction device for reaction to obtain a halohydrin; (2) saponification: saponificating the halohydrin with an alkali metal hydroxide to obtain an epoxide and an alkali metal halide; (3) performing a bipolar membrane electrodialysis of the alkali metal halide to obtain an alkali metal hydroxide and a halogen hydride. Also provided is a method for preparing an epoxide by halohydrination, the method comprising: (1) halohydrination: halohydrinating a halogen hydride, an H.sub.2O.sub.2 and an olefin compound to obtain a halohydrin; optionally, (2) saponification: saponificating the halohydrin with an alkali metal hydroxide to obtain an epoxide and an alkali metal halide; optionally, (3) performing a bipolar membrane electrodialysis of the alkali metal halide to obtain an alkali metal hydroxide and a halogen hydride. The method according to the present invention can prepare a halohydrin or an epoxide at very high selectivity and yield, and greatly reduce the amount of waste water and waste slag discharges.

Provided is a method for preparing an epoxide by halohydrination, the method comprising: (1) halohydrination: adding H.sub.2O, a halogen(s) and an olefin compound to a reaction device for reaction to obtain a halohydrin; (2) saponification: saponificating the halohydrin with an alkali metal hydroxide to obtain an epoxide and an alkali metal halide; (3) performing a bipolar membrane electrodialysis of the alkali metal halide to obtain an alkali metal hydroxide and a halogen hydride. Also provided is a method for preparing an epoxide by halohydrination, the method comprising: (1) halohydrination: halohydrinating a halogen hydride, an H.sub.2O.sub.2 and an olefin compound to obtain a halohydrin; optionally, (2) saponification: saponificating the halohydrin with an alkali metal hydroxide to obtain an epoxide and an alkali metal halide; optionally, (3) performing a bipolar membrane electrodialysis of the alkali metal halide to obtain an alkali metal hydroxide and a halogen hydride. The method according to the present invention can prepare a halohydrin or an epoxide at very high selectivity and yield, and greatly reduce the amount of waste water and waste slag discharges.

Novel biaromatic compounds, which are vitamin D analogs, processes for their preparation and cosmetic, dermatological and pharmaceutical preparations containing one or more of these compounds.

Novel biaromatic compounds, which are vitamin D analogs, processes for their preparation and cosmetic, dermatological and pharmaceutical preparations containing one or more of these compounds.