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External Chiral Ligand-Induced Enantioselective Lithiation/S E 2 Reactions of Isochroman and Phthalan.-Lithiation of isochroman and phthalan in the presence of a chiral bis(oxazoline) ligand followed by quenching with electrophiles results in asymmetric enantioselective formation of α-substituted derivatives. The method is applied to the preparation of the dopamine D 4 antagonist (R)-(VIII) (=U-101387).-(TOMOOKA, KAT-

1999 stereochemistry stereochemistry (general, optical resolution) O 0030 -050Enantioselective Reactions of α-Methoxybenzyllithium Generated by t-BuLi/Chiral Bis(oxazoline) Complex with Aldehydes. -The title reaction gives access to 1,2-diol monomethyl ethers (III) in moderate to high levels of enantioselectivity (up to 98%) and diastereoselectivity (up to 90% anti), depending on the aldehyde reactivity. The present reaction provides a new way for the asymmetric synthesis of propargylic alcohols such as (IIIc) and (IIId). The origin of the enantioselectivity is discussed in terms of a dynamic thermodynamic resolution mechanism. -(TOMOOKA,