abstract |
A compound of the formula ##STR1## wherein Hal is chlorine or bromine, R is selected from the group consisting of alkyl of 1 to 6 carbon atoms, aralkyl of 7 to 15 carbon atoms and a silylated group, K is a protective group selected from the group consisting of ##STR2## n is 2 or 3 and the wavy lines mean the groups may have either isomer form or are mixtures thereof which are intermediates for Δ 4 ,9(11),16 -pregnatriene-3-ones. |