Fe(NO3)3-Catalyzed Monoterpenes Oxidation by Hydrogen Peroxide: an Inexpensive And

Fe(NO3)3-catalyzed monoterpenes oxidation by hydrogen peroxide: an inexpensive and environmentally benign oxidative process

Danieli Marcolan Carari and *Márcio José da Silva[1]

Chemistry Department, Federal University of Viçosa, Viçosa, Minas Gerais, Brasil. 36590-0001

55 31 38993210; 55 31 38993065 (fax)

Supplementary Material

Separation and characterization of main products

The products identification was performed via GC/MS analyses (Shimadzu MS-QP 5050A mass spectrometer,operating electronic impact mode at 70 eV, coupled to a Shimadzu 17A GC) and by comparison with the authentic samples.

The products were isolated by column chromatography was carried out using 0.063-0.2 mm silica gel (DavisilR LC60A 40-63 Micron). Thin layer chromatography (TLC) was carried out using 0.2 mm Kieselgel F254 (Merck) silica plates and compounds visualized using UV irradiation at 365 nm.

Infrared spectra were recorded as neat using a FT-IR Varian 660 Fourier Transform Infrared spectrometer, at range of wavenumber of 4000 to 450 cm-1. NMR spectra were recorded at room temperature in CD3OD on a Varian Mercury 300 spectrometer operating at 300 MHz for 1H and 75 MHz for 13C. All chemical shifts are reported in parts per million (ppm) and were measured relative to the CD3OD (δ 2.49 for 1H NMR and δ 39.5 for 13C NMR). Coupling constants (J) are reported in Hertz (Hz). These data were recently reported by us [15].

Myrtenol methyl ether

1H NMR (300 MHz, CDCl3-d1): 5,39 – 5,37 (m, 1H, 3 - CH); 3,17 (s, 2H, 10 – CH2); 2,05 – 1,90 (m, 1H, 1 - CH); 1,85 – 1,81 (m, 2H, 4 – CH2); 1,80 – 1,77 (m, 1H, 7 – CH2, H7’); 1,64 (s, 3H, 11 – OCH3); 1,30 – 1,15 (m, 1H, 7 – CH2, H7); 1,09 (8,9 – CH3).

13C NMR (75 MHz, CDCl3-d1): 134,1(C2); 121,0 (C3); 76,8 (C10); 48,8 (C11); 41,6 (C1); 31,02 (C5); 27,0 (C6); 24,07 (C4); 23,5 (C7); 22,5 (C8); 22,0 (C9).

FT-IR (ART)  (cm-1): 2967; 2926; 2828; 1438; 1378; 1362; 1074.

MS/EI (m/z/rel.int.): 153/2; 136/34; 121/23; 93/29; 73/100; 59/12; 55/13; 43/31; 41/28.

Figure SP 4. 13C NMR spectrum (75 MHz,CDCl3) of myrtenol methyl ether (1a)

Figure SP 5. 1H NMR spectrum (300 MHz,CDCl3) of myrtenol methyl ether (1a)

Figure SP 6. FT-IR (ATR) spectra of myrtenol methyl ether (1a)

 - Terpineol

1H NMR (300 MHz, CDCl3-d1): 5,40 - 5,36 (m, 1H, 2 - CH); 4,13 (s, 1H, OH); 2,06 – 2,12 (m, 2H, 3 – CH2), 1,92 – 1,84 (m, 4H, 6 – CH2, 5 – CH2), 1,64 (s, 3H, 7 – CH3), 1,55 – 1,44 (m, 1H, 4 - CH), 1,19 (s, 3H, 9 – CH3), 1,17 (s, 3H, 10 – CH3).

13C NMR (75 MHz, CDCl3-d1): 134,0 (C1); 120,5 (C2); 72,8 (C8); 44,9 (C4); 31,0 (C6); 27,4 (C9); 26,9 (C3); 26,2 (C10); 24,0 (C5); 23,4 (C7).

FT-IR (ART)  (cm-1): 3383; 2965; 1677; 1455; 1249; 1158; 1077.

MS/EI (m/z/rel.int.): 136/23; 121/38; 93/51; 79/11; 59/100; 43/55.

Figure SP 7. 13C NMR spectrum (75 MHz,CDCl3) of-terpineol

Figure SP 8. FT-IR (ATR) spectra of myrtenol methyl ether (1a)

Figure SP 9. 1H NMR spectrum (300 MHz,CDCl3) of-terpineol

Effect of temperature on the Fe(NO3)3-catalyzed β-pinene oxidation reactions by H2O2 in CH3OH.

The changes in reaction temperature drastically affected the efficiency of Fe(III)- conversionup to lower values (Table SP1). At room temperature, the system becomes biphasic; however, after solvent extraction, it was verified that only a poor conversion of β-pinene was obtained (ca. 5%). Even when the reaction temperature was increased to 35 or 45 C, both maximum conversion and oxidation selectivity were lower than those obtained at 55 C.

Table SP1. Effect of temperature on the Fe(NO3)3-catalyzed β-pinene oxidation reaction with H2O2in CH3OHa

Exp. / Temperature
(°C) / Conversionb
(%) / Selectivityc
(%)
isomersb / 1a / 1b / ni / Soxidized
2 / 35.0 / 15 / 18 / 40 / 19 / 23 / 59
3 / 45.0 / 66 / 14 / 45 / 19 / 22 / 64
4 / 55.0 / 91 / 10 / 49 / 24 / 17 / 73

aReaction conditions: β-pinene (5 mmol); Fe(NO3)3 (0.020 mmol); methyl alcohol (25 mL);hydrogen peroxide (20.0 mmol); 8 hour reaction.

bDetermined by GC.

cDetermined by GC. Isomers α and γ-terpinene were formed in almost equimolar amounts; (1a) myrtenol methyl ether and (1b) α-terpineol; (ni) complex mixture of non-identified minority products;Soxidized: selectivity combined into main products.

[1] Author to whom correspondence should be addressed:

Prof. Marcio Jose da Silva, Chemistry Department, Federal University of Viçosa, Avenida PeterHenry Rolfs, s/n, Viçosa, Minas Gerais, MG, Brazil, 36570-000.

Fax: (+55)-31-3899-3065, Tel.: (+55)-31-3899-3071. E-mail: or