Studies aimed at the construction of theC-glycosidic part of nogalamycin (1) and menogarol (2) are described. The stereochemistry of the addition of aryl lithiums to 4-acetyl-1,3-dioxolane16, prepared from D-glucose via10a-15, was studied. The major isomers were the (S)-isomers17aand17bas shown by X-ray analysis of17awith the unnatural configuration. The adduct17awas further converted to the anomeric naphthoquinones22aand22bby acetal cleavage, ozonolysis, acetalization and Diels-Alder reaction with 1-methoxybutadiene.