Reactions of anthracene hydride with styrene and stilbene oxide. Reduction in benzylic position via nucleophilic substitution

Nucleophilic ring opening of oxiranes 1 and 2 by the carbanion AH^- ("anthracene hydride") proceeds rapidly giving rise to two isomeric products 3 and 5 from styrene oxide 1. In prolonged reactions, products with a 9-benzyl 9,10-dihydroanthracene structure (5, 6) are fragmented by an excess of carbanion to yield anthracene A and benzylic anions. The respective products 7 and 8 of reductive opening can be isolated in good yields with Na⁺ as gegen ion; however, they are transformed into styrenes with Li⁺. No fragmentation was observed in reactions of styrene oxide with xanthenyl anion Xan^-.