1: α-tetralon oxime With lithium diisopropyl amide in tetrahydrofuran Metallation; dilithiation; 2: methyl 4-(N-tert-butoxycarbonyl-(5S)-methyl-(2S)-pyrrolidinylmethoxy)benzoate in tetrahydrofuran Condensation; 1.5 h; 3: With hydrogenchloride Cyclization; 1 h; Heating;

1: α-tetralon oxime With lithium diisopropyl amide in tetrahydrofuran Metallation; dilithiation; 2: ethyl 4-methoxybenzoate in tetrahydrofuran Condensation; 1.5 h; 3: With hydrogenchloride Cyclization; 1 h; Heating;

1.1: 90 percent / NH2OH / ethanol; H2O / Heating 2.1: LDA / tetrahydrofuran 2.2: tetrahydrofuran / 1.5 h 2.3: 68 percent / 3N HCl / 1 h / Heating View Scheme

(i) nBuLi, THF, (ii) /BRN= 2208571/, (iii) aq. HCl; Multistep reaction;