REARRANGEMENT APPROACHES TO CYCLIC SKELETONS .9. STEREOSELECTIVE TOTAL SYNTHESIS OF (+ -)-CAMPHORENONE BASED ON A RING-CONTRACTION OF BICYCLO[3.2.1]OCT-6-EN-2-ONE - RELIABLE ONE-STEP DIAZO TRANSFER FOLLOWED BYA WOLFF REARRANGEMENT/

A direct diazo transfer reaction to bicyclo[3.2.1]oct-6-en-2-ones and related compounds was accomplished by treatments with 2,4,6-triisoprop ylbenzenesulfonyl azide and potassium t-butoxide at -78 degrees C in T HF. A Wolff rearrangement of the resulting alpha-diazoketones in the p resence of water gave ring-contraction products, bicyclo[2.2.1]heptene carboxylic acids. Using these two transformations the total synthesis of (+/-)-camphorenone was achieved stereoselectively, starting from 1- methoxybicyclo[2.2.2]oct-5-en-2-one.