SYNTHESIS OF A 3-THIOMANNOSIDE

Transcription

1 Supporting Information SYNTHESIS OF A 3-THIOMANNOSIDE María B Comba, Alejandra G Suárez, Ariel M Sarotti, María I Mangione* and Rolando A Spanevello and Enrique D V Giordano Instituto de Química Rosario, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario CONICET Suipacha 531, S2002RLK Rosario, Argentina Corresponding authors: *spanevello@iquir-conicetgovar and mangione@iquir-conicetgovar Table of contents Experimental Section S2 Synthesis of Allylic alcohol 4 S2 Synthesis of Allylic xanthate 5 S3 Synthesis of Diol 2 S3 Synthesis of Thiocarbonate 6 S3 Synthesis of Disulfide 7 S4 Synthesis of Acetylated disulfide 8 S4 Synthesis of Triacetate 11 S4 Thiomannopyranoside 1 S5 Selected spectra S6 Figure S-1: 1 H-NMR (300 MHz) of compound 4 S6 Figure S-2: 13 C-NMR (75 MHz) of compound 4 S6 Figure S-3: 1 H-NMR (300 MHz) of compound 5 S7 Figure S-4: 13 C-NMR (75 MHz) of compound 5 S7 Figure S-5: 1 H-NMR (300 MHz) of compound 2 S8 Figure S-6: 13 C-NMR (75 MHz) of compound 2 S8 Figure S-7: 1 H-NMR (300 MHz) of compound 6 S9 Figure S-8: 13 C-NMR (75 MHz) of compound 6 S9 Figure S-9: 1 H-NMR (300 MHz) of compound 7 S10 Figure S-10: 13 C-NMR (75 MHz) of compound 7 S10 S 1

2 Figure S-11: 1 H-NMR (300 MHz) of compound 8 S11 Figure S-12: 13 C-NMR (75 MHz) of compound 8 S11 Figure S-13: 1 H-NMR (300 MHz) of compound 11 S12 Figure S-14: 13 C-NMR (75 MHz) of compound 11 S12 Figure S-15: 1 H-NMR (300 MHz) of compound 1 S13 Figure S-16: 13 C-NMR (75 MHz) of compound 1 S13 Experimental Section All reagents and solvents were used directly as purchased or purified according to standard procedures Analytical thin layer chromatography was carried out using commercial silica gel plates (Merck, Silica Gel 60 F254) and visualization was effected with short wavelength UV light (254 nm) and p-anysaldehyde solution with subsequent heating Flash column chromatography was performed with silica gel 60 H (Merck) using EtOAc:hexanes mixtures NMR spectra were recorded at 300 MHz for 1 H, and 75 MHz for 13 C on a Bruker Avance-300 DPX spectrometer with as solvent and (CH 3 ) 4 Si ( 1 H) as internal standard Chemical shifts are reported in delta (δ) units in parts per million (ppm) and splitting patterns are designated as s, singlet; d, doublet; t, triplet; q, quartet; and m, multiplet Coupling constants are recorded in Hertz (Hz) The structure of the products were determined by a combination of spectroscopic methods such as IR, 1D and 2D NMR (including NOE, COSY, HSQC and HMBC experiments) and HRMS Infrared spectra were recorded on a Shimadzu IR Prestige-21 spectrometer using sodium chloride plate pellets Absorbance frequencies are recorded in reciprocal centimeters (cm 1 ) High resolution mass spectra (HRMS) were obtained on a Bruker microtof-q II LC-MS spectrometer Optical rotations were determined using a JASCO DIP-1000 digital polarimeter in 100 mm cells and the sodium D line (589 nm) at room temperature in the solvent and concentration indicated The melting points were taken on a Leitz Wetzlar Microscope Heating Stage Model 350 apparatus and are uncorrected Levoglucosenone 3 was obtained according to the procedure previously described 16 Synthesis of Allylic alcohol 4 Compound 3 (594 g, 4713 mmoles) was dissolved in MeOH (32 ml) and cooled at 0 ºC CeCl 3 7H 2 O (1756 g, 4713 mmoles) and NaBH 4 (142 g, 377 mmoles) were added and stirred for 25 h The solution was neutralized with HCl 01 N to reach ph = 7 The mixture was diluted with water (5 ml) and extracted several times with 50 ml portions of EtOAc The combined organic extracts were dried (Na 2 SO 4 ) and concentrated The residue was purified by flash chromatography to afford 4 (559 g, 4360 mmoles, 92%) as a white crystalline solid; Rf (60% hexane- EtOAc) 017; mp = ºC (ethyl ether) [Lit ºC] 29 ; [α] D (c 0995, CHCl 3 ) [Lit - 34 (c 100, CHCl 3 )] 29 ; max (KBr) 3445 (OH), 3420, 1628 (C=C), 1122, 1066, 1045 cm -1 ; H (300 MHz ) 612 (1H, dd, J 98, 43 Hz, ), 570 (1H, ddd, J 98, 24, 22 Hz, H-3), 551 (1H, dd, J 27, 22 Hz, ), 466 (1H, dd, J 43, 42 Hz, H-5), 433 (1H, s, H-2), 384 (1H, d, J 66 Hz, endo), 375 (1H, dd, J 66, 42 Hz, exo), 215 (1H, s, OH); C (75 MHz ) 1306 (C-4), 1290 (C-3), 1011 (), 711 (C-2), 705 (C-6), 686 (C-5) S 2

3 Synthesis of Allylic xanthate 5 To a solution of compound 4 (126 g, 984 mmoles) in 10 ml of anhydrous THF was added a suspension of NaH (60% dispersion in mineral oil) (086 g, 1970 mmoles) in 40 ml of anhydrous THF The mixture was cooled at 0 ºC CS 2 (15 ml, 2460 mmoles) and CH 3 I (215 ml, 3450 mmoles) were added The mixture was stirred during 3 h and then a solution of NH 4 Cl (sat) (2 ml) was added The solution was extracted with EtOAc (100 ml) and then washed with 5 ml of brine The combined organic extracts were dried (Na 2 SO 4 ) and concentrated The residue was purified by flash chromatography to afford 5 (201 g, 922 mmoles, 94%) as a white crystalline solid; Rf (60% hexane- EtOAc) 056; mp = ºC (diisopropylether) [α] D (c 1145, CHCl 3 ); max (KBr) 3000, 2968, 2908, 1653 (C=C), 1288, 1208 (C=S), 1120, 882 cm -1 ; H (300 MHz ) 636 (1H, s, H-2), 627 (1H, dd, J 98, 41 Hz, ), 579 (1H, s, ), 576 (1H, d, J 98 Hz, H-3), 473 (1H, dd, J 43, 41Hz, H-5), 402 (1H, d, J 64 Hz, endo), 382 (1H, dd, J 64, 43 Hz, exo), 259 (3H, s, SCH 3 ); C (75 MHz ) 2158 (C=S), 1332 (C-4), 1238 (C-3), 983 (), 793 (C-2), 713 (C-5), 711 (C-6), 191 (SCH 3 ); HRMS (EI, MH + ) MH + found , C 8 H 11 O 3 S 2 + calcd Synthesis of Diol 2 Compound 5 (795 mg, 364 mmoles) was dissolved in acetone:h 2 O 95:5 mixture (257 ml), NMO was added and then a solution of OsO 4 in t BuOH was added (920 mg, 004 mmoles) The mixture was stirred during 72 h and then cooled at 0 ºC Na 2 SO 3 was added and after 10 min the solution was filtered The residue was purified by flash chromatography to afford 2 (861 mg, 342 mmoles, 94%) a white crystalline solid; Rf (60% Hexane-EtOAc) 008; mp = ºC (diisopropylether); [α] D (c 1095, CHCl 3 ); max (KBr) 3534 (OH), 3442 (OH), 2973, 2959, 2928, 2896, 1477, 1409, 1332, 1311, 1283, 1208 (C=S), 1088, 915cm -1 ; H (300 MHz ) 563 (1H, dd, J 83, 17 Hz, H-2), 560 (1H, d, J 17 Hz, ), 472 (1H, ddd, J 51, 19, 16 Hz, H-5), 409 (1H, s, H-3), 400 (1H, s, ), 386 (1H, dd, J 81, 51 Hz, exo), 381 (1H, dd, J 81, 16 Hz, endo), 306 (1H, s, OH), 302 (1H, s, OH), 260 (3H, s, SCH 3 ); C (75 MHz ) 2170 (C=S), 983 (), 832 (C-2), 762 (C-5), 705 (C-3), 679 (C-4), 655 (C-6), 193 (SCH 3 ); HRMS (EI MNa + ) found C 8 H 12 O 5 S 2 Na + calcd Synthesis of Thiocarbonate 6 Xanthate 2 (190 mg, 075 mmoles) was dissolved in AcOH (12 ml) and cooled at 0 ºC in an ice-bath A solution of H 2 SO 4 /AcOH 50 % (78 ml) was added and the mixture was stirred for 6 h at room temperature The mixture was cooled to 0º C in an ice bath and diluted with EtOAc (150 ml) Solid NaHCO 3 (10 g) was added and after 10 minutes of stirring, the base was dissolved with water and the phases were separated The organic layer was washed with 5% aqueous NaHCO 3 (2 x 50 ml), brine (50 ml) and dried (Na 2 SO 4 anh) After filtration, the solvents were concentrated under reduced pressure The residue was purified by flash chromatography to afford compound 6 (1243 mg, 050 mmoles, 67%) as white crystalline solid; Rf (60%, hexane:etoac) 021; [ ] D (c 11, CHCl 3 ); max (KBr) 2981, 2843, 1748 (C=O), 1357, 1223, 1206, 1160, 1023, 841 cm 1 ; H (300 MHz CDC1 3 ) 556 (1H, d, J 23 Hz, H- 1), 500 (1H, s, ), 469 (1H, dd, J 86, 23 Hz, H-2), 466 (1H, dd, J 58 Hz, H-5), 432 (1H, dd, J 86 Hz, H-3), 430 (1H, dd, J 84 Hz, endo), 388 (1H, dd, J 84 Hz, 58 Hz, exo), 215 (3H, s, ); C (75 MHz, ) 1703 (C=O), 1698 ( ), 980 (), 744 (C-5), 742 (C-2), 698 (C-4), 661 (C-6), 453 (C-3), 208 ( ); HRMS (EI, MNa + ): MNa +, found C 9 H 10 O 6 SNa + calcd S 3

4 Synthesis of Disulfide 7 Compound 6 (88 mg, 036 mmoles) was dissolved in anhydrous CH 3 OH (12 ml) and anhydrous K 2 CO 3 (86 mg, 062 mmoles) was added The mixture was stirred for 3 h at room temperature under argon atmosphere After completion (according to TLC analysis) the reaction mixture was filtered over a Celite pad and washed with aliquots of CH 3 OH The combine filtrates were concentrated under reduced pressure obtaining colorless oil This compound was used without further purification in the next reaction step For structural characterization an aliquot of crude product 7 was suspended in methyl tert-butyl ether and stirred overnight to obtain compound 7 as an off-white solid; max (KBr) 3342 (OH), 2926, 1635, 1558, 1386, 1078 cm 1 ; H (300 MHz, H 2 O) 532 (1H, s, ), 455 (1H, d, J 51 Hz, H- 5), 443 (1H, d, J 81 Hz, endo), 430 (1H, s, ), 411 (1H, d, J 67 Hz, H-2), 366 (1H, dd, J 51, 77 Hz, exo), 336 (1H, d, J 67 Hz, H-3), 327 (1H, s, OH), 183 (1H, s, OH); C (75 MHz, H 2 O) 1012 (), 768 (C-5), 713 (C-4), 671 (C-2), 656 (C-6), 568 (C-3), HRMS (EI, MK + ): MK +, found C 12 H 18 KO 8 S 2 + calcd Synthesis of Acetilated disulfide 8 Crude product 7 (88 mg) was dissolved in anhydrous CH 2 Cl 2 (18 ml) and the distilled pyridine (08 ml) was added at room temperature Ac 2 O (04 ml, 357 mmoles) and DMAP (11 mg, 009 mmoles) were added and the solution was stirred overnight under argon atmosphere The mixture was treated with HCl 50% (1 ml) and extracted with EtOAc (3 x 30 ml) The combined organic layers were dried (Na 2 SO 4 anh) and concentrated under reduce pressure The resulting residue was purified by flash chromatography to afford compound 8 (71 mg, 020 mmoles, 55% two steps) as a white crystalline solid; 8: R f (60% hexane/ EtOAc) 032; [ ] D (c 11, ); mp º C (CH 2 Cl 2 /hexane); max (KBr) 1734 (C=O), 1375, 1361, 1247, 1236, 1153 cm 1 ; H (300 MHz, ) 541 (1H, bs, ), 524 (1H, s, ), 488 (1H, dd, J 13, 70 Hz, H-2), 463 (1H, d, J 51 Hz, H-5), 449 (1H, d, J 80 Hz, endo), 377 (1H, dd, J 51, 80 Hz, exo), 359 (1H, d, J 70, 80 Hz, H-3), 217 (3H, s, ), 208 (3H, s, ); C (75 MHz, ) 1702 (COCH3), 1701 (COCH3), 996 (), 751 (C-5), 724 (C-4), 704 (C-2), 659 (C-6), 486 (C-3), 211 ( ), 205 ( ); HRMS (EI, MNa + ): MNa +, found C 20 H 26 NaO 12 S 2 + calcd Synthesis of Triacetate 11 Compound 8 (25 mg, 005 mmoles) was dissolved in anhydrous THF (6 ml) and cooled to 0º C LiAlH 4 (18 mg, 050 mmoles) was added and the resulting suspension was stirred at room temperature for 16 h The mixture was cooled to 0º C, diluted with EtOAc (25 ml) and the excess of reducing agent was destroyed by addition of methanol (25 ml) Finally, the mixture was neutralized with AcOH and solvents were concentrated under reduced pressure The resulting residue was dissolved in anhydrous pyridine (07 ml) and Ac 2 O (07 ml) and catalytic amount of DMAP was added The mixture was stirred for 16 h at room temperature The reaction was concentrated and the residue was dissolved in CH 2 Cl 2 (20 ml) and washed with water (2 x 10 ml) The organic layer was dried (Na 2 SO 4 anh) S 4

5 and the solvent was concentrated under reduced pressure The residue was purified by flash chromatography to give compound 11 (176 mg, 006 mmoles, 57% two steps) as a colorless oil; R f (60% hexane/etoac) 039; [ ] D (c 06, ); max (liquid film) 1735 (C=O), 1691, 1373, 1217, 1062 cm 1 ; H (300 MHz, ) 545 (1H, s, ), 515 (1H, dd, J 16, 71 Hz, H-2), 486 (1H, bs, ), 457 (1H, d, J 54 Hz, H-5), 429 (1H, d, J 71 Hz, H-3), 427 (1H, d, J 84 Hz, endo), 378 (1H, dd, J 54, 84 Hz, exo), 235 (3H, s, ), 217 (3H, s, ), 210 (3H, s, ); C (75 MHz, ) 1929 ( ), 1688 ( ), 1682 ( ), 988 (), 737 (C-5), 731 (C-4), 675 (C-2), 649 (C-6), 411 (C-3), 292 ( ), 201 ( ), 196 ( ); HRMS (EI, MNa + ): MNa +, found C 12 H 16 NaO 7 S + calcd Synthesis of Thiomannopyranoside 1 Compound 11 (55 mg, 018 mmoles) was dissolved in Ac 2 O (18 ml) under argon atmosphere The solution was cooled at 0 ºC and 2 drops of TMSOTf were added The mixture was stirred for 1 h at room temperature Then, the reaction mixture was treated with a saturated solution of NaHCO 3 (1 ml) and extracted with EtOAc (3 x 10 ml) The combine organic layers were dried (Na 2 SO 4 anh) and the solvent was concentrated under reduce pressure The residue was purified by flash chromatography to give 1 (576 mg, 016 mmoles, 88%) as a colorless oil; R f (60% hexane/etoac) 06; [a] D (c 11, ); max (liquid film) 1749 (C=O), 1371, 1217 cm 1 ; H (300 MHz, ) 601 (1H, d, J 17 Hz, ), 517 (1H, dd, J 97, 114 Hz, ), 500 (1H, dd, J 17, 30 Hz, H-2), 426 (1H, dd, J 30, 114 Hz, H-3), 422 (1H, m, ), 408 (1H, m, H-5), 405 (1H, m, ), 231 (3H, s, ), 217 (3H, s, ), 213 (3H, s, ), 205 (3H, s, ); 201 (3H, s, ); C (75 MHz, ) 1934 ( ), 1706 ( ), 1696 (2 ), 1682 ( ), 896 (), 713 (C-5), 708 (C-2), 656 (C-4), 623 (C-6), 437 (C-3), 305 ( ), 209 ( ), 207 ( ), 206 ( ), 205 ( ); HRMS (EI, MNa + ): MNa +, found C 16 H 22 NaO 10 S + calcd S 5

6 Selected spectra H-5 H-3 H- TMS OH ppm Figure S-1: 1 H spectrum of 4 in C-4 C-3 C-2 C-6 C ppm Figure S-2: 13 C spectrum of 4 in S 6

7 SCH 3 H-3 H-2 H-5 TMS ppm Figure S-3: 1 H spectrum of 5 in C-4 C-3 C-5 C-2 C-6 SCH 3 C=S ppm Figure S-4: 13 C spectrum of 5 in S 7

8 SCH 3 H-2 H-5 H-3 OH TMS ppm Figure S-5: 1 H spectrum of 2 in C-3 C-4 C-2 C-5 C-6 SCH 3 C=S ppm Figure S-6: 13 C spectrum of 2 in S 8

9 H-2 H-5 H-3 TMS ppm Figure S-7: 1 H spectrum of 6 in C-5 C-2 C-4 C-6 C ppm Figure S-8: 13 C spectrum of 6 in S 9

10 OH -OH H-2 H-3 H ppm Figure S-9: 1 H spectrum of 7 in D 2 O C-5 C-4 C-2 C-6 C ppm Figure S-10: 13 C spectrum of 7 in D 2 O S 10

11 CDCl H-2 H-5 H-3 TMS ppm Figure S-11: 1 H spectrum of 8 in C-4 C-5 C-2 C-6 C ppm Figure S-12: 13 C spectrum of 8 in S 11

12 H-3 H-2 H ppm Figure S-13: 1 H spectrum of 11 in C-5 C-4 C-2 C-6 C ppm Figure S-14: 13 C spectrum of 11 in S 12

13 H-2 H-5 H ppm Figure S-15: 1 H spectrum of 1 in C-5 C-2 C-4 C-6 C ppm Figure S-16: 13 C spectrum of 1 in S 13