Total Synthesis of (+)-Colletodiol: New Methodology for the Synthesis of Macrolactones

Article abstract of DOI:10.1021/jo00265a033

Synthetic efforts directed toward two different structures suggested for the macrocyclic bis(lactone) colletodiol are detailed.The initial approach to an incorrect structure (C₁₁ epi) relies upon the manipulation of methyl α-D-glucopyranoside to set the required stereochemistry for the C₈-C₁₄ segment of the C₁₁ epi structure.The second approach, initiated after structural revision based upon X-ray crystallographic evidence, employs a Lewis acid mediated addition of allylstannane 33 to β-alkoxy aldehyde 34 to set the stereochemistry of the C₈-C₁₄ subunit.This route, which employs a number of new synthetic reactions developed specifically for this problem, gives (+)-colletodiol in nine linear operations and 8.2percent overall yield.