1. , C. A. , and C. Chch, 075 g) and anti-213 (13%, 0.044 g) as white solids in 73% overall yield (0.247 g) and as a 45 : 55 mixture of syn/anti diastereoisomers Data for compound syn-213 : m, CH 2 Cl 2 ), Rf = 0.7 (AcOEt), [?] D 23 = -63.4 (CH 2 Cl 2 , c = 0.5). 1 H NMR (CDCl 3 , 500MHz) ? = 6.90 5.16 (br s, 1H, COCH 2 CHCH A H B ), 5.13 (dd, J = 1.2, 5.3 Hz, 1H, COCH 2 CHCH A H B, pp.2-6

C. Om, 1. , and C. A. , 77 (br s, 1H, NH), 5.73 (d, J = 5, = +56.9 (CH 2 Cl 284 (d, J = 1.2 Hz, 1H, 2-H), 5.88 (m, 1H, COCH 2 CHCH 2 ) 1H, COCH 2 CHCH A H B ), 5.17 (d, J = 5.7 Hz, 1H, COCH 2 CHCH A H B ) 2H, COCH A H B CHCH 2 and COCH A H B CHCH 2 ) ppm. 13 C NMR (CDCl 3 , 125 MHz) ? =, p.29, 2019.

1. , C. A. , C. Ochm, 1. , C. A. et al., OC 2 H 5 ), 3.72-3.67 (m, 2H, OCH 2 OCH A H B CH 3 and OCH 2 OCH A H B CH 3, OCH 3 ) 3.84 (s), 2.68 (br s, 2H, NH and OH), 1.24 (t, J = 6.9 Hz, 3H, OCH 2 OCH 2 CH 3 ), 1.19 (t, J = 7.1 Hz, 3H, OCH 2 OCH 2 CH' 3 ) ppm. 13 C NMR (CDCl 3 , 125 MHz) ? = 148.8 (ArC), p.8165

. 5s, 8-dimethoxy-10-(2-methoxy-2-oxoethylthio)-3-oxo-3,5,10,10a- tetrahydro-1H-oxazolo[3,4-b]isoquinoline-5-carboxylate 233a and (5S,10S,10aR)-methyl 7,8-dimethoxy-10-(2-methoxy-2-oxoethylthio)-3-oxo-3, 234b : A solution of methyl thioglycolate, pp.10-11

. 5s, 10aR)-methyl-10-hydroxy-7,8-dimethoxy-3-oxo-3,5,10,10a-tetrahydro-1H- oxazolo[3,4-b]isoquinoline-5-carboxylate 236 : A solution of ketone 224

. Ml, 11 mmol) in dry THF (10 mL) was added dropwise at -20°C. The mixture was stirred for 1 hour, and then MeI (14.8 g, 105.34 mmol) contained in THF (21 mL) was added dropwise After stirring for an additional time of 1 hour, H 2 O (100 mL) was added. The mixture was then extracted with ether (3 × 100 mL) The organic layers were washed with 1N NaOH (150 mL), dried over MgSO 4 and evaporated. The crude residue was purified by flash column chromatography (silica gel, cyclohexane) 247 as colourless crystals (5, MHz) ? = 6.58 (d, 1H, J = 8.3 Hz, ArH), 6.25 (d, 1H, J = 8.3 Hz, ArH), 5.90 (s, 2H, OCH 2 O), 3.77 (s, 3H, OCH 3 ), 2.11 (3H, s, CH 3 ). 13 C NMR (CDCl 3 , 75 MHz) ? = 154.0 (ArC), pp.44-45

M. Och, Anal. calcd. for C 9 H 10 O 3 C 65.05; H 6.07 %, found C 65.45; H 6.48 %. 6-methoxy-7-methylbenzo[d][1,3]dioxole-5-carbaldehyde 81 : 49a,51 POCl 3 was added dropwise at 0°C (4.2 mL, 45.2 mmol) to a stirred anhydrous DMF solution (10 mL) After stirring at room temperature for 30 min

H. Nmrs, 1. , and C. , 300 MHz) ? = 1011 (s, 1H, ArH), 6.03 (s, 2H, OCH 2 O), 3.84 (3H, s, OCH 3 ), 2.19 (3H, s, CH 3 ). 13 C NMR (75 MHz

. Naoh, 62 mL) and H 2 O (1.86 mL) were added at 0°C until a white solid appears

1. Dd, J. =. Odd, 1. , J. =. , C. Chnm et al., 63 (s, 3H, OCH 3, MHz) ? = 6.47 (s 13 C NMR (CDCl 3 , 125 MHz) ? = 151.69 (ArC), pp.4-5549339950391152460408

1. , R. , 2. , 2. , J. =. 1h et al., 1 H NMR (CDCl 3 , 500 MHz) ? = 7, 4.60 (m, 1H, CHCH 2 N), pp.88-92, 1975.

C. A. Hz, 77 (s, 3H, OCH 3, p.96

2. Dd, J. =. 1h, O. A. , O. A. Ndd, 1. et al., isoindole-1,3-dione 265 : A solution of tetrahydroisoquinoline 264 (200 mg, 0.335 mmol) and MeONa (36 mg, 0.67 mmol : 1, 8 mL) was stirred overnight at room temperature. The mixture was then diluted in CH 2 Cl 2 (20 mL), washed with brine, and dried over Na 2 SO 4 , evaporated and purified by filtration to yield 265 (86 mg, 63%), m.p. 215°C, R f = 0.8 (MeOH/CH 2 Cl 2 : 1 : 60). 1 H NMR (500 MHz, CDCl 3 ) ? = 7, MeOH/CH 2 Cl.9 Hz, CH A H B OH), 2.91 (m, 1H, CH 2 CHN), pp.90778449-90778450

C. Chn, 18 (s, 3H, CH 3 ) 13 C NMR (125 MHz, CDCl 3 ) ? = 169, 2C, NCO)

C. Hz, 1. Ndd, J. =. Ndd, 1. , and J. Cl, 68 (s, 3H, OCH 3, pp.4-81635938

+. Cl, HRMS (EI) calcd. for C 22 H 19 ClN 2 O 5 [M] + 426.0982, found 426.0979. 2-isopropoxy-6-methylphenol 80 : 152 To a solution of 3-methylcatechol, p.4166

H. Nmrd, 6. , and J. =. , 300 MHz) ? = 616 (s, 3H, CH 3, 1H, OH), 4.42 (sept, 1H, J = 6.1 Hz CH(CH 3 ) 2 ) Hz CH(CH 3 ) 2 ). 13 C NMR (75 MHz, CDCl 3 ) ? = 145.2 (ArC)CH 3 ) 2 ), pp.74-72

I. Acoh, 150 mL) and HMTA (10.54 g, 75.3 mmol) was stirred at 100°C for 96 hours After this period, the solution was cooled and a saturated solution of NaHCO 3 was added, The Chapitre, vol.4

C. Ohdd, 1. , and J. =. Oh, Then24 g, 32.6 mol) in Et 2 O (60 mL), under an atmosphere of argon After stirring at room temperature for 4h 2N NaOH (1.3 mL) and H 2 O (3.9 mL) were added at 0°C until a white solid appears. The mixture was then filtered and the solid was washed with CH 2 Cl 2 (3×30 mL), dried over Na 2 SO 4 , evaporated to yield 252 as a pale yellow oil (684 mg, 83 %). 1 H NMR (500 MHz, CDCl 3 ): ? = 6.60 (s, 1H, ArH), 26 mmol) was reduced with LiAlH CH 2 Cl 2 (60 mL), H 2 O (1.3 mL) 1H, ArH), 4.53 (m, 1H, CH(CH 3 ) 2 ), 3.79 (s, 3H, OCH 3 ) 3.09 (m, 1H, CH(CH 3 ) 2 ), pp.59406450-59406452

1. and O. Oh, in 1 : 1 mixture of MeOH/CH 2 Cl 2 (9 mL), was stirred overnight at room temperature under 5 bars of H 2 atmosphere After the catalyst was filtered, washed with MeOH and dried over Na 2 SO 4 and evaporated. to give 76 as a colourless oil (110 mg, 98%). 1 H NMR (MeOD, 500 MHz) ? = 6, 532 mmol) and 10% Pd/C (64 mg) 1H, J = 1.4 Hz, ArH), 6.59 (d, 1H, J = 1.4 Hz, ArH), 4.93 (s, 4H, NH 2 and 2 OH), 3.77 (s, 3H, OCH 3 ), pp.71-74