"Isoretinol" and retinal: an unorthodox but simple route to the vitamin A series

"Isoretinol" I was prepd. in 55% yield by methylation of II, obtained by reaction of III with the (chlorodihydrofuryl)copper IV. Oxidn. of I with Me2SO contg. N,N'-dicyclohexylcarbodiimide gave a stereoisomeric mixt. of retinal. Similarly, Me2C:CHCH2CH2CMe:CHCH:C:CMeCH2CH2OH was prepd. from geranyl bromide and IV and oxidized to give 4,5-dehydrofarnesal, Me2C:CHCH2CH2CMe:CHCH:CHCMe:CHCHO, which was reduced to give 4,5-dehydrofarnesol, Me2C:CHCH2CH2CMe:CHCH:CHCMe:CHCH2OH. [on SciFinder (R)]