The alkylation stereochemistry of 9-alkyl-10-lithio-9, lO-dihydroanthracene has often been explained on the basis of inverting, boabshaped anion models. Recent carbon-13 NMR data for these anions has led to the suggestion of a flattened, sp2-hybridized model, and alkylation studies herein are presented in support of this model. Since recent molecular mechanics calculations have indicated a wide range of central ring folding for 9, lO- ...
