Inexpensive retinyl acetate has been subjected to transesterification
followed by allylic oxidation to give retinal in 98% yield
as a 92:8 mixture of all-trans/13-cis isomers after chromatographic separation.
More convenient methods of isolating the all-trans isomer
have also been employed.
retinyl acetate - retinal - transesterification - allylic oxidation - isomerization