4-hydroxy-5-methyl-5-octylthiophen-2-one

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To 32 (50 mg, 0.21 mmol) and benzyl bromide (37 mL, 0.31 mmol) following General Procedure H, was obtained 76 (49 mg, 75%) after flash chromatography (15% EtOAc/Hex). 1H NMR (300 MHz, CDCl3) δ 0.86 (t, J=6.9 Hz, 3H), 1.24 (m, 11H), 1.41-1.48 (m, 1H), 1.66 (s, 3H), 1.79-1.86 (m, 2H), 4.98 (s, 2 H), 5.39 (s, 1H), 7.31-7.42 (m, 5H); 13C NMR (100 MHz, CDCl3) δ 14.1, 22.6, 25.0, 26.4, 29.1, 29.3, 29.4, 31.8, 38.8, 59.7, 74.0, 102.2, 127.6, 128.8, 128.8, 134.3, 185.8, 194.1. IR (NaCl) 2928, 1681, 1610 cm−1.

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To 32 (46 mg, 0.19 mmol) dissolved in hexanes was added triethylamine (43 μL, 0.31 mmol) and trimethylsilylchloride (36 μL, 0.29 mmol) and the solution was allowed to stir at room temperature for 4 h. The mixture was filtered over celite and evaporated to provide 5-methyl-5-octyl-4-trimethylsilanyloxy-5-H-thiopen-2-one which was redissolved in CH2Cl2 (0.4 mL). To this mixture was added isopropyl isocyanate (19.2 mL, 0.19 mmol) and the solution was allowed to stir at room temperature for 2 hours. NH4Cl(sat) (5 mL) was added and the mixture was extracted with CH2Cl2 (3×10 mL). The organics were combined, dried (MgSO4), filtered and evaporated to give crude 71. Flash chromatography (20% EtOAc/2% AcOH/Hexanes) gave pure 71 (35 mg, 60%). 1H NMR (300 MHz, CDCl3) δ 0.85 (t, J=7.0 Hz, 3H), 1.14-1.24 (m, 17H), 1.45 (m, 1H), 1.63 (s, 3H), 1.76-1.79 (m, 2H), 3.81-3.88 (m, 1H), 5.16 (d, J=7 Hz, 1H), 6.33 (s, 1H). 13C NMR (75 MHz, CDCl3) δ 13.9, 20.4, 22.5, 22.8, 25.1, 25.9, 29.1, 29.3, 29.5, 31.8, 38.7, 44.0, 60.2, 111.6, 149.7, 176.2, 194.5. The mixture was filtered over celite evaporated

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To 32 (91 mg, 0.37 mmol), methyl chloroformate (63 μL, 0.81 mmol), dimethylaminopyridine (DMAP) (23 mg, 0.18 mmol) and NEt3 (108 μL, 0.77 mmol) following General Procedure L was obtained 70 (66 mg, 59%, 79% based on recovered starting material) after flash chromatography (30% EtOAc/2% AcOH/Hexanes-10% THF/2% AcOH/EtOAc). 1H NMR (300 MHz, MeOD) δ 0.86 (t, J=6.9 Hz, 3H), 1.20 (bs, 12H), 1.35 (s, 3H), 1.55 (m, 1H), 1.71-1.75 (m, 1H), 3.59 (s, 3H); 13C NMR (75 MHz, MeOD) δ 13.3, 21.8, 24.4, 27.0, 28.5, 28.6, 29.0, 30.2, 31.0, 50.4, 58.3, 124.6, 168.1, 187.7, 196.7. HRMS (EI) m/z calculated for C15H24O4S+) 300.1389 obsd. 300.1375.

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: (66, 67). To 32 (247 mg, 1.02 mmol) dissolved in hexanes was added triethylamine (0.23 mL, 1.68 mmol) and trimethylsilylchloride (0.21 mL, 1.64 mmol) and the solution was allowed to stir at room temperature for 4 h. The mixture was filtered over celite and evaporated to provide 5-methyl-5-octyl-4-trimethylsilanyloxy-5-H-thiopen-2-one. To a solution of TiCl4 (0.7 mL, 0.7 mmol) in CH2Cl2 (1.95 mL) at −78° C. was added acetaldehyde (54 μL, 0.97 mmol) and this solution was allowed to stir for 5 min at −78° C. Then, 5-methyl-5-octyl-4-trimethylsilanyloxy-5-H-thiopen-2-one dissolved in CH2Cl2 (0.4 mL) was cannulated into TiCl4/acetaldehyde solution giving a bright orange color. This mixture was allowed to warm and stir for 20 min at 0° C. The mixture was poured into NH4Cl(sat) (15 mL) and extracted with CH2Cl2 (3×15 mL). The organics were combined, dried (MgSO4), filtered and evaporated. Flash chromatography (10% EtOAc/Hexanes) provided pure 66 (34 mg) and 67 (24 mg) (50%). (66) 1H NMR (300 MHz, CDCl3) δ 0.86 (t, J=6.9 Hz, 3H), 1.05-1.08 (m, 1H), 1.24 (bs, 11H), 1.49 (d, J 6.5 Hz, 3H, rotamer) 1.55 (d, J=5.2 Hz, 3H, rotamer), 1.62 (s, 3H), 1.78-1.82 (m, 2H), 4.68 (q, J=6.5 Hz, 1H, rotamer), 5.04 (q, J=5.2 Hz, 1H, rotamer). HRMS (ES) m/z calculated for C16H28O3SNa+ (M+CH2+Na+) 323.1660 obsd. 323.1660. The mixture was filtered over celite evaporated

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: From 32 (40 mg, 0.17 mmol) and propionyl chloride (20 μL, 0.22 mmol) following general procedure K was obtained 64 (23.1 mg, 47%) after flash chromatography (15% EtOAc/Hexanes). 1H NMR (300 MHz, CDCl3) δ 0.85 (t, J=7 Hz, 3H), 1.12-1.25 (m, 13H), 1.42-1.49 (m, 2H), 1.64 (s, 3H), 1.78-1.84 (m, 2H), 2.57 (q, J=7.5 Hz, 2H), 6.39 (s, 1H); 13C NMR (75 MHz, CDCl3) δ 8.71, 14.0, 22.6, 25.1, 25.9, 27.9, 29.1, 29.3, 29.5, 31.8, 38.6, 60.4, 113.8, 169.1, 177.0, 179.9. IR (NaCl) 2928, 1787, 1688 cm−1; Analysis Calculated for C16H26O3S: C, 64.4; H, 8.78; Found: C, 64.3; H, 8.89.

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: From 32 (47 mg, 0.18 mmol) and 3-iodo-1-chlorobutane (40 μL, 0.36 mmol) following general procedure H was obtained 41 (46 mg, 85%) after flash chromatography (20% EtOAc/Hexanes). 1H NMR (300 MHz, CDCl3) δ 0.86 (t, J=7 Hz, 3H), 1.07-1.27 (m, 1H), 1.24 (s, 10H) 1.48-1.51 (m, 1H), 1.62 (s, 3H), 1.75-1.82 (m, 2H), 1.89-1.98 (m, 4H), 3.59 (t, J=5.9 Hz, 2H), 3.95-3.98 (m, 2H), 5.28 (s, 1H); 13C NMR (75 MHz, CDCl3) δ 14.1, 22.6, 25.1, 26.0, 26.5, 29.0, 29.2, 29.3, 29.5, 29.7, 31.8, 44.1, 59.6, 71.7, 101.6, 186.1, 193.8. Analysis Calculated for C17H29C2S: C, 61.3; H, 8.78, Found: C, 61.9; H, 9.01.