TY - JOUR A1 - Clark-Lewis, JW A1 - Spotswood, TM A1 - Williams, LR T1 - Flavan Derivatives. VII. The Stereochemical Course of the Synthesis of 2,3-cis-Flavan-3,4-trans-diol Diacetates, and the 2,4-cis-Stereochemistry of Flavan-4β-ols JF - Australian Journal of Chemistry JO - Aust. J. Chem. Y1 - 1963 VL - 16 IS - 1 SP - 107 EP - 111 KW - UR - https://doi.org/10.1071/CH9630107 N2 - Lithium aluminium hydride reduces 2,3-trans-3-bromo-4'-methoxy-6-methyl-flavanone to 2,3-trans-3,4-trans-3-bromo-4'-methoxy-methylflvan-4-ol which is converted by acetic anhydride-potassium acetate into 3,4-trans-diacetoxy-4'-methoxy-6-methyl-2,3-cis-flavan. Similar reactions with the 3',4'-dimethoxy analogue give 3,4-trans-diacetoxy-3',4'-dimethoxy-6-methyl-2,3-cis-flavan. The corresponding cis-bromoflavanones are reduced to 2,3-cis-3,4-cis-3-bromoflavan-4-ols. ER -