OLIGOMERIC FLAVANOIDS .25. CLEAVAGE OF THE ACETAL FUNCTIONALITY IN A-TYPE PROANTHOCYANIDINS

Authors
STEYNBERG PJ CRONJE A STEYNBERG JP BEZUIDENHOUDT BCB BRANDT EV FERREIRA D
Citation
Pj. Steynberg et al., OLIGOMERIC FLAVANOIDS .25. CLEAVAGE OF THE ACETAL FUNCTIONALITY IN A-TYPE PROANTHOCYANIDINS, Tetrahedron, 53(7), 1997, pp. 2591-2598
Citations number
18
Categorie Soggetti
Chemistry Inorganic & Nuclear
Journal title
Tetrahedron → ACNP
ISSN journal
00404020
Volume
53
Issue
7
Year of publication
1997
Pages
2591 - 2598
Database
ISI
SICI code
0040-4020(1997)53:7<2591:OF.COT>2.0.ZU;2-6
Abstract
The hepta-O-methyl ethers 3 and 4 of procyanidin A-1 1 and A-2 2 are s ubject to facile cleavage of the acetal functionality with sodium cyan oboranuide in trifluoroacetic acid at 0 degrees C. This straight forwa rd chemical method permits the unambiguous establishment of the absolu te configuration of the DEF-flavanyl unit and the D-ring carbon and ox ygen atoms that are involved in the double linkage of the A-class proa nthocyanidins. (C) 1997, Published by Elsevier Science Ltd.