New synthetic possibilities for the preparation of liquid ctystalline dicyclohexyl derivatives

A new synthetic approach for the preparation of two- and three ring liquid crystalline compounds possessing trans,trans-dicyclohexyl moiety is proposed and realised. Recently discovered reaction of Grignard reagents with. esters leading to 1-substituted cyclopropanoles in the presence of tetraisopropoxytitanium was used as a key stage. Starting from ethyl trans-4-alkylcyclohexancarboxylates the corresponding 6-(4alklcyclohexyl)-3-alkyl (or aryl) cyclohex-2-en-1-ones have been prepared Their catalytic hydrogenation in the base media gave mainly saturated trans,trans-ketones which are liquid crystalline and have been used also as a promising intermediate products for the preparation of different kinds of other LC compounds.