Synthesis and stereochemistry of decarestrictines H and J.

The first synthesis of (7 S ,9 R )-decarestrictine H and (7 R ,9 R )-decarestrictine H as well as the improved synthesis of decarestrictine J were achieved. The overall yields of (7 S ,9 R )-decarestrictines H and J were 20.9% each in nine to ten steps from ( R )-Roche ester using a unified synthetic route via esterification with 3,3-ethylenedioxyhex-5-enoic acid and ring-closing metathesis, which were the key steps. The relative stereochemistry of decarestrictine H was determined to be 7,9- syn by comparing the spectral data of the natural product and synthetic epimers of decarestrictines H. [ABSTRACT FROM AUTHOR]