ELECTROPHILIC REACTIONS OF 4-METHYL-A-HOMO-4-AZACHOLEST-4A-EN-3-ONE

Nitration, bromination and oxidation reactions of 4-methyl-A-homo-4-az acholest-4a-en-3-one (1) were studied. The reaction with acetyl nitrat e gave products of cis addition to the double bond accompanied by the A-seco compounds. The results of bromination were dependant on the rea ction conditions, After the initial electrophilic attack at C-5, furth er transformations involved the addition of a nucleophile, which was f ollowed by isomerization to the A-seco compounds or rearrangement to t he six-membered lactams or lactone promoted by AgBF4. The CrO3 oxidati on yielded the product of a double bond cleavage. (C) 1997 Elsevier Sc ience Ltd.