Preparation of a polymer-supported diol and its use in isolating aldehydes and ketones from mixtures and as a protecting group for aldehydes and ketones

Abstract

Reaction of cross-linked chloromethylated polystyrenes with 3-mercaptopropane-1,2-diol and sodium hydroxide under phase-transfer conditions gave polymers containing diol residues. A range of aldehydes and ketones were successfully bound to these polymers via acetal formation. The aldehydes and ketones were released by treating the products with aqueous dioxane in the presence of toluene-p-sulphonic acid. The polymer-supported diol could be used to isolate aldehydes or ketones from mixtures with other compounds and to separate a 3-oxosteroid from a 17- or a 20-oxosteroid. The supported diol was successfully used to protect the aldehyde group of undec-10-enal whilst the terminal vinyl group was transformed into –CH₂CH₂OCOPh. Attempts to monoprotect dicarbonyl compounds were unsuccessful.