Synthesis of Polyhydroxylated Carbocyclic Derivatives with Large Rings

5 Synthesis of Polyhydroxylated Carbocyclic Derivatives with Large Rings 

Preparation of an HCS by a Wittig-type methodology and subsequent standard transformations into a linear derivative should give the di-olefin ready for the RCM cyclization. 

This compound can be oxidized to di-aldehyde 95 and further converted into di-olefin 96. Such activated derivatives should (potentially) cyclize under either McMurry (compound 95) or RCM (for 96) conditions. 

FIGURE 1031 Synthetic strategies to polyhydroxylated di-olefin and di-aldehyde. 

Removal of the protecting group from the Cl position in compound 93 was performed by acetolysis, a method commonly used in sugar chemistry. Treatment of 93 with acetic anhydride and H2S04(cat.) afforded the expected mixture of di-acetates 

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