Steynberg, Jan P.; Burger, Johann F. W.; Young, Desmond A., Heterocycles, 1989, vol. 28, # 2, p. 923 - 935
作者:Steynberg, Jan P.、Burger, Johann F. W.、Young, Desmond A.、Brandt, Edward V.、Ferreira, Daneel
DOI:——
日期:——
Synthesis of condensed tannins. Part 1. Stereoselective and stereospecific syntheses of optically pure 4-arylflavan-3-ols, and assessment of their absolute stereochemistry at C-4 by means of circular dichroism
作者:Jacobus J. Botha、Desmond A. Young、Daneel Ferreira、David G. Roux
DOI:10.1039/p19810001213
日期:——
Stereoselective and also stereospecific condensation at C-4 of flavan-3,4-diols of known absolute configuration with phloroglucinol and resorcinol in acid medium proceeds at ambient temperatures with partial retention of configuration for 2,3-trans-isomers and with inversion for 2,3-cis-analogues. Circular dichroism spectra of the resultant 4-arylflavan-3-ols all exhibit multiple Cotton effects. The