Part I. Efforts Directed Towards the Total Synthesis of Shionone. Part II. Conversion of Estrone to Androst-4-En-3-One: A New Method for Activating the C-9 and C-10 Positions of Estrogenic Steroids for Substitution

Citation

Kowalski, Conrad John (1974) Part I. Efforts Directed Towards the Total Synthesis of Shionone. Part II. Conversion of Estrone to Androst-4-En-3-One: A New Method for Activating the C-9 and C-10 Positions of Estrogenic Steroids for Substitution. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/XM7S-7224. https://resolver.caltech.edu/CaltechTHESIS:07162014-113619903

Abstract

Part I: An approach to the total synthesis of the triterpene shionone is described, which proceeds through the tetracyclic ketone i. The shionone side chain has been attached to this key intermediate in 5 steps, affording the olefin 2 in 29% yield. A method for the stereo-specific introduction of the angular methyl group at C-5 of shionone has been developed on a model system. The attempted utilization of this method to convert olefin 2 into shionone is described.

Part II: A method has been developed for activating the C-9 and C-10 positions of estrogenic steroids for substitution. Estrone has been converted to 4β,5β-epoxy-10β-hydroxyestr-3-one; cleavage of this epoxyketone using an Eschenmoser procedure, and subsequent modification of the product afforded 4-seco-9-estren-3,5-dione 3-ethylene acetal. This versatile intermediate, suitable for substitution at the 9 and/or 10 position, was converted to androst-4-ene-3-one by known procedures.

Thesis Files