Cyclohexanol → 4-(Bromomethyl)cyclohexan-1-ol

Participants

Reaction Steps

Modified polyvinylbutryal containing a pendant group with cyclohexanol was prepared by the reaction of PVB with tetrahydropyranyl (THP) protected bromomethylcyclohexanol, followed by acid hydrolysis of the THP protection group. The THP-protected cyclohexanol-containing moiety was prepared by the following reaction sequence: 4-Methoxycyclohexanoic acid was reduced with borane-tetrahydrofuran complex to obtain 4-bromomethyl-cyclohexanol. This compound was treated with phosphorus tribromide to obtain the corresponding bromo compound. This bromo compound was reacted with trimethylsilyliodide to cleave the methoxy group to obtain 4-bromomethyl-cyclohexanol, which in turn was treated with dihyhdropyran to obtain the tetrahydropyranyl-protected bromomethylcyclohexanol. This preparation is represented by the following reaction scheme and further described in paragraphs a-d below. ##STR15## a) Preparation of 4-bromomethylcyclohexanol (C-3): 4-Methoxycyclohexanoic acid (13.0 g) was dissolved in THF (20 g), and cooled with ice. Then, borane-tetrahydrofuran complex (80 ml of 1M solution) was added and stirred overnight. Excess borane was destroyed by adding 15 ml of water dropwise until no effervescence was observed. The solution was then neutralized with potassium carbonate. The THF layer was dried over anhydrous magnesium sulfate and filtered. The solvent from the filtrate was removed under vacuum to obtain the desired 4-methoxycyclohexylmethanol (12.0 g).

Provenance & Evidence