STEREOCHEMISTRY OF 3-BROMOFLA VANONES, 3-BROMOFLAVAN4-OLS AND FLAVAN -3 : 4-DIOLS

Two isomeric 6-methyl-4-methoxy-3-bromoflovanones have been synthesised and on the basis of conversion of one into the other and their infra-red data, conformations have been assigned to them. These bromollavanones have farther been reduced to the corresponding-3-brornoflavan 4-ols and on the basis of chemical reactions and physical data, conformations have been assigned to these bromohydrins. One of the above bromohydrins has been converted into the corresponding flavan-3 :4-diol diacetate. Further, the stereochemistry of all the four racemates of 6-methyl-e-methoxyflavan-3:4 diol has been discussed and:conformations assigned fa them.