24-Nor-5beta-chol-22-enes derived from the major bile acids by oxidative decarboxylation

The preparation of 24-nor-5beta-chol-22-enes from formyloxy-5beta-cholanic acids by oxidative decarboxylation with lead tetraacetate is described. NMR data is presented with other physical constants for the norcholenes derived from cholic, chenodeoxycholic, ursodeoxycholic, hyodeoxycholic, and deoxycholic acids. The facile synthesis of these norcholenes demonstrates the applicability of the formyloxy protecting group to oxidative decarboxylations in the bile acid series.