In connection with a program directed toward the total synthesis of steroidal alkaloids and related steroidal derivatives (1.2.3). we have been interested in developing a synthesis of the veratrum alkaloids.
This latter group provides an interesting challenge since its members possess the C-nor-&how steroid skeleton, a unique system among tha various members of the steroidal alkaloid class. We would now like to present a successful synthesis of the C-nor-D-home intermediates VIIa and VIIb which we feel show promise as useful intermediates for the synthesis of veratrum alkaloids. In a previous report (2) we had described the total synthesis of the keto-acetate, I, and had indicated the potential use of this intermediate, in the synthesis of ring'C modified steroidal derivatives. The exptiimants described below provide support for this proposal. The keto-acetate, I, was reduced (NaBH.4 in aqueous methanol) and the crude alcohol acetate was inmediately dehydrated to the olefin, II, by means of phosphorus pentoxide in rafluxing benzene. The crystalline olefin$* * Part IV in the series entitled "Total Synthesis of Steroidal Derivatives". ** Satisfactory elemental analyses were obtained for all new compounds reported.