Iron ( III ) Porphinate / H 202-Mediated Conversion of All-( Zs )-Retinol

The reaction of hydrogen peroxide with all-(£)-retinol (1) catalyzed by (meso-tetraphenylporphinato)iron(III) led to the formation of 4-hydroxyretinol (2), 4-oxoretinol (3), 5,8-epoxyretinol (4), 5,6-epoxyretinol (5), 3-dehydroretinol (6), all-(£)and 12-(Z)-retroretinol (7/7a) as well as all-(£')and 12-(Z)-anhydroretinol (8/8 a) as major non-volatile products. The con­ version products were characterized by comparison of their chromatographic (HPLC) and spectroscopic data (UV; MS; 'H and 13C NMR) with those of synthesized reference com­ pounds. The observed product formation supports the hypothesis of a C4 centered radical as the key intermediate of all-(£')-retinol conversion.