Epoxy-retinoic acid

D7 5,8-Epoxy retinoic acid [3012-76-8] 5,8-Epoxy-5,8-dihydroretinoic acid... 

The conversion of frans-retinyl acetate into retinoic acid in hamster organ culture,262 and of cis- and trans-rzimoxc acid into the 5,6-epoxy- and 4-oxo-derivatives and their glucuronides has been demonstrated.263 264 Strains of Aspergillus niger metabolize ionones and related compounds to oxygenated derivatives, some of which may be useful intermediates for carotenoid synthesis. The asymmetric oxidation of p-ionone to (25, 6/ ,7/ )-2,7-epoxydihydro-a-ionone (218) has been demonstrated.265 (i )-4-Hydroxy-p-ionone (219 X = OH)... 

Several papers have described the synthesis of epoxyretinoids. The 5,6-epoxides of fmns-retinal (88) and its (9Z)-, (IIZ)-, and (13Z)-isomers were prepared by direct epoxidation of retinal with w-chloroperbenzoic acid. The 7,8-epoxides (89) of retinal, retinol, and retinoic acid and its methyl esters were synthesized from the jS-ionone epoxide (90). The exceedingly labile methyl 13,14-epoxy-13,14-dihydroretinoate (91) was made by addition of the epoxyaldehyde (92) to the phosphorane (93). Chromogen 574 , a product of the epoxidation of retinol first described in 1945, has now been identified as the... 

Chien and Amin (1980) have reported the preparation of 5,6-epoxy-5,6-dihydroretinoic acid (LXIII) labeled with tritium in position 11. The compound was readily obtained from the tritiated retinoic acid by epoxidation with mono-perphthalic acid (Fig. 17). 

Epoxy-5,6-dihydro-retinoic acid (D6) -Acetylretinyl amine (Bl), retinaldehyde acetylhydrazone (C8), axerophthene (A7)... 

The metabolism of several other synthetic retinoids has been briefly examined but not analyzed to any great extent. Included are studies in rats of the hydrolysis of retinoic acid anhydride to retinoic acid (Premachandra and Cama, 1975), the conversion in hamsters of retinaldehyde acetylhydrazone (C8) and (V-acetyl-retinylamine (Bl) to retinol and retinyl esters (Roberts etal., 1978), the metabolism of 15-methyl retinone, 15-methylretinol, and 15,15-dimethylretinol (AlO) and the excretion of their metabolites in the bile and urine of rats (Tosukhowong and Olson, 1978), and the metabolism of 5,6-epoxy-5,6-dihydroretinol and retinaldehyde both in rats (Jungalwala and Cama, 1965 Lakshmanan et ai, 1965) and in cultured, spontaneously transformed mouse fibroblasts (Bhat et al., 1981). Because of the lack of extensive metabolic studies, these reactions are not discussed further here. 

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