THE CHEMISTRY OF BINOR-S AND ITS CYCLOPROPYL RING TRANSFORMATIONS

Selective ring opening of the cyclopropyl moiety of binor-S was accomp lished by several methods including acidic hydrolysis, bromination, an d hydrobromination. The crystal structure of dibromide adduct 3 was so lved by X-ray diffraction analysis. Debrominations of 3 yielded either 1 or 4a, whereas dehydrobromination yielded a 3-substituted monobromi de 6a. The mechanism of conversion of 3 to 6a is depicted as involving intermediate 7; the existence of 7 is supported by the isolation of o lefin 8. Oxidation of alcohol 4c produced ketone 11a which was either oxidized to lactone 12 or transformed to a methylene derivative 11b. H ydroboration of 11b followed by quenching with hydrogen peroxide produ ced a hydroxymethyl derivative 14.