NMR data are reported for the major Bt1 isomer; white needles (from EtOH); yield, 90%;

mp 94-95 C; []25D = +30.5 (c 1.64, CHC13); 1H NMR 6 1.02-1.14 (m, 5H), 1.53-1.67

(m, 5H), 1.90 (br s, 1H), 2.41 (dd, J= 8.8, 6.8 Hz, 1H), 2.65-2.77 (m, 2H), 2.99 (dd, J=

13.4, 6.1 Hz, 1H), 3.43-3.48 (m, 1H), 3.70 (s, 2H), 5.31, 5.49 (AB, J= 13.5 Hz, 2H),

7.20-7.48 (m, 8H), 8.04 (d, J= 8.2 Hz, 1H); 13C NMR 6 24.4, 24.6, 25.8, 31.6, 31.7,

41.1, 56.3, 61.4, 61.5, 65.1, 72.3, 109.8, 119.8, 123.8, 126.3, 127.3, 128.4, 129.1, 133.4,

138.8, 145.8. Anal. Calcd for C23H29N5: C, 73.57; H, 7.78; N, 18.65. Found: C, 73.94; H,

8.17; N, 18.77.

 1-{[(5S)-3,5-Dibenzyltetrahydro-1H-imidazol-1-yl]methyl}-lH-1,2,3-

benzotriazole (3.12c): white microcrystals (from EtOH); yield, 96%; mp 81-82 C;

[a]25D= +40.8 (c 1.87, CHC13); 1H NMR 6 2.34 (dd, J= 9.4, 6.5 Hz, 1H), 2.67-2.81 (m,

2H), 2.92 (dd, J= 13.2, 6.6 Hz, 1H), 3.42, 3.52 (AB, J= 13.2 Hz, 2H), 3.52-3.60 (m,

1H), 3.62, 3.70 (AB, J= 6.3 Hz, 2H), 5.38, 5.43 (AB, J= 13.6 Hz, 2H), 7.12-7.45 (m,

13H), 8.05 (d, J= 8.1 Hz, 1H); 13C NMR 6 41.3, 57.8, 58.6, 61.8, 65.5, 73.9, 109.8,

119.8, 123.8, 126.3, 127.0, 127.3, 128.2, 128.3, 128.4, 129.2, 133.4, 138.3, 138.8, 145.9.

Anal. Calcd for C24H25N5: C, 75.17; H, 6.57; N, 18.26. Found: C, 75.03; H, 6.32; N,

18.30.

3.4.3 General Procedure for the Preparation of 1,2,3,5,10,10a-Hexahvdroimidazo[ 1,5-
blisoquinolines 3.1a-c.

 A mixture of 3.12a-c (1.0 mmol) and anhyd AlC13 (0.40 g, 3.0 mmol) was stirred

in dry CH2C12 (20 mL) refluxing for 12 h. After cooling, the reaction mixture was added

CH2C12 (30 mL) and the organic layer was washed with 2 M NaOH, brine and dried over

anhydrous K2CO3. After removal of the solvent in reduced pressure, the crude product