92944-23-5Relevant academic research and scientific papers
Termination of Biomimetic Cyclizations by the Allylsilane Function. Formation of the Steroid Nucleus in One Step from an Acyclic Polyenic Chain
Johnson, William S.,Chen, Yu-Qun,Kellogg, Michael S.
, p. 6653 - 6656 (1983)
The aim of this project was to modify the cyclization substrate 1, which is known to undergo ring closure to give 2a and 2b, in such a way that a five- instead of six-membered ring D is formed, thus resulting in the construction of the complete steroid nucleus.The substrate 5 was first prepared as shown in Scheme I, but it gave a very complicated mixture of cyclization products.However, the substrate 18, which was obtained as depicted in Scheme II, afforded the tetracyclic products 24 and 25 in >34percent yield.The steroidal constitution of the nucleus of these products was established by their transformation into the known 17α- and 17β-vinylandrostenones 36, which are convertible into progesterone.
