Retinoids allenic

Okamura et al. synthesized allenic retinoids and studied the thermally induced pericyclic reactions of these compounds (Sueiras and Okamura, 1980). 

In studying the linking of (401) with (402), it was recognized that when tetrahydrofuran was used as a solvent, the coupling reaction was suppressed. It is probably for this reason that the reaction of (401) with (407) in tetrahydrofuran gives (408) instead of the desired allene. However, the cuprate (407) cannot be prepared in other solvents. Allenic retinoids have also been postulated as reaction products in the elimination and isomerization of acetylenic retinoids (Sueiras and Okamura, 1980). 

Kennedy, M.W., Allen, J.E., Wright, A.S., McCruden, A.B. and Cooper, A. (1995a) The gpl5/400 polyprotein antigen of Brugia malayi binds fatty acid and retinoids. Molecular and Biochemical Parasitology 71, 41-50. 

Although allenic carotenoids, for example, fucoxanthin (Isler, 1977) which occurs in many brown and freshwater algae, have long been known, and fucoxanthin itself is the most commonly encountered carotenoid, specific syntheses of retinoids with allenic structural elements have only been reported very recently. 

Removal of the protective group by means of tetrabutylammonium fluoride and final purifications by HPLC, gave the allenic alcohol (406), which underwent thermolysis to give 12-s-cis-locked retinoids. 

Willhite CC, Sharma RP, Allen PV, Berry DL (1990) Percutaneous retinoid absorption and embryotoxicity. J Invest Dermatol 95 (5) 523-529... 

Haraoui B, Wilder RL, Allen JB, Spom MB, Helfgott RK, Brinkerhoff CE (1985) Dose-dependent suppression by the synthetic retinoid, 4-hydroxyphenyl retinamide, of streptococcal cell wall-induced arthritis in rats. Immunopharmacology 7 909-916... 

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