Oligomeric flavanoids. Part 15a. Base-catalyzed pyran rearrangements of procyanidin B-2, and evidence for the oxidative transformation of B- to A-type procyanidins

Johann F.W. Burger; Herbert Kolodziej; Richard W. Hemingway; Jan P. Steynberg; Desmond A. Young; Daneel Ferreira

doi:10.1016/s0040-4020(01)87771-1

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Oligomeric flavanoids. Part 15^a. Base-catalyzed pyran rearrangements of procyanidin B-2, and evidence for the oxidative transformation of B- to A-type procyanidins

Informally Refereed

Authors:

Johann F.W. Burger, Herbert Kolodziej, Richard W. Hemingway, Jan P. Steynberg, Desmond A. Young, Daneel Ferreira

Year:

1990

Type:

Scientific Journal

Station:

Southern Research Station

DOI:

https://doi.org/10.1016/s0040-4020(01)87771-1

Source:

Tetrahedron 46(16):5733-5740

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Abstract

Procyanidin B-2 3 is subject to facile C-ring isomerizations in 0.1M NaHCO₃ solution to form a novel series of 3,4,9,1o-tetrahydro-2H,8H-pyrano[2,3-h]chromenes 7, 9, and 10. The low percentage conversion of B- to A-type procyanidin 2 is rationalized in terms of an initial oxidative removal of hydride ion at C-2 (C-ring).

Citation

Burger, Johann F.W.; Kolodziej, Herbert; Hemingway, Richard W.; Steynberg, Jan P.; Young, Desmond A.; Ferreira, Daneel. 1990. Oligomeric flavanoids. Part 15^a. Base-catalyzed pyran rearrangements of procyanidin B-2, and evidence for the oxidative transformation of B- to A-type procyanidins. Tetrahedron 46(16):5733-5740