GB774408A - A process for the preparation of endocylic polyols - Google Patents

Abstract

Endocyclic polyols and diols are prepared by reacting an ethylenically unsaturated endocyclic aldehyde or ketone with carbon monoxide and hydrogen under increased pressure and at elevated temperature in the presence of a cobalt catalyst to effect hydroformylation, and subjecting the hydroformylation product to a subsequent catalytic hydrogenation. Endocyclic aldehydes and ketones which may be used are bicyclo - (1,2,2) - hept - 5 - ene - 2 - aldehyde and its 3-methyl-, 3-isopropyl-, 3-phenyl-, 2-methyl-, 3-methyl-2-ethyl-, 4 : 7 : 7-trimethyl-, and 3 : 4 : 7 : 7 - tetramethyl - derivatives, bicyclo - (1,2,2) - hept - 5 - ene - 2 - one and its 4 : 7 : 7 - trimethyl - derivative, bicyclo - (2,2,2)-oct - 5 ene - 2 - aldehyde and its 3 - methyl - derivative, bicyclo - (2,2,2) - oct - 5 - ene - 2 - one, cyclopentadienequinone, cyclohexadienequinone, bis - cyclohexadienequinone, the 2-acetyl-, 2-benzoyl-, 3-methyl-2-acetyl-, 7 : 7-dimethyl - 2 - acetyl - and 2 - (hexahydrobenzoyl)- derivatives of bicyclo-(1,2,2)-hept-5-ene, and the 2-acetyl- and 3-methyl-2-acetyl-derivatives of bicyclo-(2,2,2)-oct-5-ene. The hydroformylation step may be carried out discontinuously or continuously at a temperature between 100 DEG and 225 DEG C., at pressures between 100 and 700 atmospheres, using the cobalt catalyst in the form of the metal or as a cobalt compound such as cobalt carbonyl or cobalt carbonyl hydride. The ratio of carbon monoxide to hydrogen may vary from 4 : 1 to 1 : 4 and solvents such as dioxane, benzene, toluene, heptane, octane, cyclohexane, ether and saturated alcohols may be used. The hydroformylation products contain the corresponding dialdehyde or keto-aldehyde formed by addition of the formyl group to the unsaturated endocyclic aldehyde or ketone and hydrogenation of the double linkage, and may also contain saturated and unsaturated alcohols and aldehyde-alcohols. The crude hydroformylation product is then hydrogenated in the presence of hydrogenation catalysts such as copperchromium catalysts to form the corresponding diols or polyols which are separated by fractional distillation. In an example, bicyclo(1,2,2) - hept - 5 - ene - 2 - aldehyde is dissolved in dioxane and subjected to the process of the invention to yield finally a mixture of diol isomers having the empirical formula C9H16O2.