Synthesis, circular dichroism and absolute stereochemistry of chiral spiroaromatic compounds. 9,9′-Spirobifluorene derivatives

Abstract

The chiral spiroaromatic compounds (+)-2 and (+)-3 with 9,9′-spirobifluorene skeletons have been synthesized and their absolute stereostructures have been unambiguously determined to be R, by application of the CD exciton chirality method; the R absolute stereochemistry of (–)-[6,6]-vespirene 1 was established by chemical correlation with these compounds.