Retinol retrosynthetic

For the side-chain of retinol acetate, there are four options to cut the double bond system retrosyntheticaUy (Fig. 7.28). [55] Four double bonds give theoretically rise to 16 stereoisomers. Knowing that disubstituted (Z)-double bonds, as in jS-carotene, are isomerised under milder conditions than trisubstituted ones, limits the retrosynthetic choices. 

The retrosynthetic analysis of retinol acetate reveals eight options for the carbonyl building block and its matching phosphorane. 

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