A simple spiroepoxide as methionine aminopeptidase-2 inhibitor: synthetic problems and solutions

The preparation of a simple 1-oxa-spiro[2.4]heptane derivative is described. Observations made in the course of the synthesis show again that apparently minor structural modifications of the dienic substrate exert a strong influence on the ring-closing metathesis outcome and that the efficient construction of even simple but highly substituted systems by RCM may constitute a synthetic challenge.