Spiroketal reductive ring opening

George Pettit, Anthony H. Albert, Peter Brown

Research output: Contribution to journalArticle

19 Citations (Scopus)

Abstract

Both the direction and mechanism of reductive ring opening with the spiroketal 9,9-dimethyl-1,6-dioxaspiro[4.5]decane (8) have been explored. With dimedone (3) as precursor, synthesis of spiroketal 8 was realized by way of intermediates 4,5,6, and 7. Lithium aluminum hydride-aluminum chloride catalyzed reduction of spiroketal 8 was found to yield tetrahydropyran 9 in contrast to the steroidal sapogenins which undergo reductive cleavage of the tetrahydropyran ring. The mechanism of ring opening was examined using deuterium labeling (8→9b) combined with mass and proton magnetic resonance spectral measurements. Reductive ring opening of spiroketal 8 was thereby found to proceed by transfer of reagent hydride directly to the spirocarbon. The experimental results also suggested that reductive ring opening of relatively nonhindered spiroketals related to 8 may offer a new synthetic route to certain substituted tetrahydropyrans.

Original languageEnglish (US)
Pages (from-to)8095-8099
Number of pages5
JournalJournal of the American Chemical Society
Volume94
Issue number23
StatePublished - 1972

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Hydrides
Aluminum chloride
Deuterium
Labeling
Lithium
Nuclear magnetic resonance
Aluminum
Sapogenins
Protons
Magnetic Resonance Spectroscopy
spiroketal

ASJC Scopus subject areas

  • Chemistry(all)

Cite this

Pettit, G., Albert, A. H., & Brown, P. (1972). Spiroketal reductive ring opening. Journal of the American Chemical Society, 94(23), 8095-8099.

Spiroketal reductive ring opening. / Pettit, George; Albert, Anthony H.; Brown, Peter.

In: Journal of the American Chemical Society, Vol. 94, No. 23, 1972, p. 8095-8099.

Research output: Contribution to journalArticle

Pettit, G, Albert, AH & Brown, P 1972, 'Spiroketal reductive ring opening', Journal of the American Chemical Society, vol. 94, no. 23, pp. 8095-8099.
Pettit, George ; Albert, Anthony H. ; Brown, Peter. / Spiroketal reductive ring opening. In: Journal of the American Chemical Society. 1972 ; Vol. 94, No. 23. pp. 8095-8099.
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