Bufadienolides. 2. 20-Hydroxy-21-nor-5α-cholanic acid γ-lactones (24→20)

George Pettit, Brian Green, George L. Dunn

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

Sodium borohydride reduction of both methyl 3β,23-diacetoxy-20-oxo-21-nor-5-cholenate (1a) and the corresponding 23-methyl ether 1b was found to produce 3β,20-dihydroxy-21-nor-5-cholenic acid γ-lactone (24 → 20). Concomitant elimination of the 23 substituent (to yield lactone 2a) again occurred with methyl 3β,23-diacetoxy-20-oxo-21-nor-5α-cholanate (3) to give γ-lactone 4a, which was also obtained by palladium-catalyzed hydrognation of olefin 2a. Hydrogenation of methyl 3β-acetoxy-20-oxo-21-nor-5-trans-22-choladienate (5) gave 5α-cholanate 6a as a major product accompanied by small quantities of 3-deoxycholanate 6b and γ-lactone 4b. Sodium borohydride reduction of ketone 6a yielded γ-lactone 4b, thereby confirming structures assigned to lactones 2 and 4. Platinum-catalyzed hydrogenation of 23-methyl ether 1b and of 23-acetate 3 led, respectively, to 23-substituted lactones 4c and 4d. A potentially useful lactone (3-oxo-4-ene, 8) for biological evaluation was obtained by Oppenauer oxidation of alcohol 2a.

Original languageEnglish (US)
Pages (from-to)1377-1380
Number of pages4
JournalJournal of Organic Chemistry
Volume35
Issue number5
StatePublished - 1970

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Bufanolides
Lactones
Methyl Ethers
Hydrogenation
cholanic acid
Palladium
Alkenes
Platinum
Ketones
Acetates
Alcohols

ASJC Scopus subject areas

  • Organic Chemistry

Cite this

Bufadienolides. 2. 20-Hydroxy-21-nor-5α-cholanic acid γ-lactones (24→20). / Pettit, George; Green, Brian; Dunn, George L.

In: Journal of Organic Chemistry, Vol. 35, No. 5, 1970, p. 1377-1380.

Research output: Contribution to journalArticle

Pettit, George ; Green, Brian ; Dunn, George L. / Bufadienolides. 2. 20-Hydroxy-21-nor-5α-cholanic acid γ-lactones (24→20). In: Journal of Organic Chemistry. 1970 ; Vol. 35, No. 5. pp. 1377-1380.
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