Steroids and Related Natural Products. VIII. Synthesis of Oxasteroids

George R. Pettit, T. R. Kasturi

Research output: Contribution to journalArticle

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Abstract

Peroxydisulfuric acid oxidation of testosterone propionate, progesterone, and cholest-4-en-3-one has been shown to yield 3-oxo-17²-hydroxy-4-oxa-5±-androstane (I, after saponification), 3,20-dioxo-4-oxa-5±-pregnane (V) and 3-oxo-4-oxa-5±- cholestane (VII) respectively. Boron trifluoride etherate-lithium aluminum hydride reduction of δ-lactones I, V, and VII led to the corresponding tetrahydropyran derivatives (IIb, VIa, and VIII). Similar reduction of 3β-hydroxy-l 7-oxo-17α-oxa-d- homo-5α-androstane (XI) gave 3β-hydroxy-17a-oxa-D-homo-5α-andro8tane (XIIa). Diborane-boron trifluoride etherate was also found to reduce lactones to cyclic ethers, while reduction with diborane gave hemiacetals. Evidence in support of the structures and stereochemistry assigned to the lactones and their unusual reduction products has been summarized. A tentative mechanism is proposed for lactone → ether reduction employing diborane-boron trifluoride etherate.

Original languageEnglish (US)
Pages (from-to)4557-4563
Number of pages7
JournalJournal of Organic Chemistry
Volume26
Issue number11
DOIs
StatePublished - Nov 1961
Externally publishedYes

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ASJC Scopus subject areas

  • Organic Chemistry

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