11-(tert-butyl-dimethyl-silanyloxy)-2,4,6,8,10,12-hexamethyl-5-oxo-docosa-2,6,8-trienoic acid 4-(tert-butyl-dimethyl-silanyloxy)-2,3-bis-(4-methoxy-benzyloxy)-1-(4-methoxy-benzyloxymethyl)-butyl ester