Upgrading biomass to high-added value chemicals: synthesis of monoterpenes-based compounds using catalytic green chemical pathways

Unusual Cascade Reactions of 8-Acetoxy-6-hydroxymethyllimonene with Salicylic Aldehydes: Diverse Oxygen Heterocycles from Common Precursors

“…26 +66 (c 1.0, CHCl 3 ). 1 H NMR (CDCl 3 , 400 MHz): δ 7.41 (1H, dm, J 15,14 = 7.4 Hz, H15), 7.11−7.18 (1H, m, H13), 6.92− 6.86 (1H, m, H14), 6.74 (1H, dd, J 12,13 = 8.2 Hz, J 12.14 = 1.2 Hz, H12), 5.45−5.52 (1H, m, H5), 4.47 (1H, s, H1), 3.87 (1H, dm, 2 J = 11.0 Hz, H2′), 3.76 (1H, dd, 2 J = 11.0 Hz, J 2,3 = 2.1 Hz, H2), 2.30 (1H, dm, 2 J = 19.0 Hz, H6′), 2.09−2.16 (1H, m, H3), 1.83 (1H, dm, 2 J = 19.0 Hz, H6), 1.76 (1H, dm, 2 J = 11.6 Hz, H8′), 1.69−1.74 (3H, m, Me16), 1.64 (1H, dd, 2 J = 11.6 Hz, J 8,3 = 3.2 Hz, H8), 1.33 (3H, s, Me18), 1.28 (3H, s, Me17). 13 [3,2-c]pyran-4-yl)phenol (−)-20a.…”

“…The NMR spectra of compound (−)-20a was recorded for its mixture with compound (−)-21a in the ratio (−)-20a/(−)-21a = 1.9:1. 1 H NMR (CDCl 3 , 600 MHz): δ 8.40 (1H, s, OH), 7.16−7.11 (1H, m, H17), 6.93−6.90 (1H, m, H19), 6.85−6.79 (2H, m, H16, H18), 4.67 (1H, s, H2), 4.09 (1H, br.d, 2 J = 11.9 Hz, H4′), 3.65 (1H, dd, 2 J = 11.9 Hz, J 4,5 = 1.8 Hz, H4), 2.30−2.25 (1H, m, H1), 2.00 (1H, sept, J 11,12 = J 11,13 = 6.9 Hz, H11), 1.95−1.84 (2H, m, H5, H6′), 1.72−1.66 (1H, m, H8′), 1.62−1.58 (2H, m, H6, H8), 1.49 (3H, s, Me10), 0.911 and 0.905 (6H, 2d, J 12,11 = J 13,11 = 6.9, Me12, Me13). 13 The reaction mixture was stirred depending on the experimental conditions.…”

“…White powder; mp 84 °C with decomposition; [α] D 25 +71 (c 0.2, CHCl 3 ). 1 H NMR (CDCl 3 , 400 MHz): δ 7.03 (1H, dm, J 15,14 = 7.9 Hz, H15), 6.84 (1H, dd, J 14,13 = J 14,15 = 7.9 Hz, H13), 6.76 (1H, dd, J 13,14 = 8.1 Hz, J 13.15 = 1.7 Hz, H13), 5.50−5.45 (1H, m, H5), 4.46 (s, 1H, H1), 3.85 (1H, dm, 2 J = 10.9 Hz, H2′), 3.81 (3H, s, Me19), 3.74 (1H, dd, 2 J = 10.9 Hz, J 2,3 = 2.1 Hz, H2), 2.34 (1H, dm, 2 J = 19.1 Hz, H6′), 2.13−2.08 (1H, m, H3), 1.85 (1H, dm, 2 J = 19.0 Hz, H6), 1.76 (1H, dm, 2 J = 11.7 Hz, H8′), 1.72−1.67 (3H, m, Me16), 1.62 (1H, dd, 2 J = 11.6 Hz, J 8,3 = 3.2 Hz, H8), 1.40 (3H, s, Me18), 1.30 (3H, s, Me17). 13 C{ 1 H} NMR (CDCl 3 , 100 MHz): δ 147.8 (s, C12), 142.0 (s, C11), 133.9 (s, C4), 123.5 (d, C5), 122.5 (s, C10), 119.7 (d, C14), 118.6 (d, C15), 110.5 (d, C13), 81.2 (s, C9), 78.6 (d, C1), 69.4 (t, C2), 55.8 (q, C19), 36.7 (d, C3), 35.0 (s, C7), 31.1 (t, C8), 27.5 (t, C6), 23.0 (q, C18), 22.0 (q, C17), 21.6 (q, C16).…”

“…The NMR spectra of compound (−)-20c was recorded for its mixture with compound (−)-21c in the ratio (−)-20c/(−)-21c = 3:1. 1 H NMR (CDCl 3 , 400 MHz): δ 6.89 (1H, dd, J 19,18 = 7.8 Hz, J 19,17 = 1.5 Hz, H19), 6.82 (1H, dd, J 18,17 = 8.0 Hz, J 18,19 = 7.8 Hz, H18), 6.76 (1H, dd, J 17,18 = 8.0 Hz, J 17,19 = 1.7 Hz, H17), 6.67 (1H, s, OH), 4.67 (1H, d, J 2,1 = 1.7 Hz, H2), 4.06 (1H, br.d, 2 J = 11.9 Hz, H4′), 3.62 (1H, dd, 2 J = 11.9 Hz, J 4,5 = 1.5 Hz, H4), 2.31−2.23 (1H, m, H1), 1.97 (1H, sept, J 11,12 = J 11,13 = 6.9 Hz, H11), 1.91−1.81 (2H, m, H5, H6′), 1.66−1.62 (1H, m, H6), 1.57−1.43 (2H, m, 2H8), 1.50 (3H, s, Me10), 0.90 and 0.88 (6H, 2d, J 12,11 = J 13,11 = 6.9 Hz, Me12, Me13). 13 1 ,3,5a,10b-hexahydrofuro[4,3,2-kl]xanthene (+)-7c.…”

“…Colorless oil; [α] D 26 +10 (c 0.5, CHCl 3 ). 1 H NMR (CDCl 3 , 500 MHz): δ 6.94−6.88 (2H, m, H19,H20), 6.84 (1H, dd, J 18,19 = 7.1 Hz, J 18,20 = 2.5 Hz, H18), 5.67−5.64 (1H, m, H11), 4.47 (1H, s, H5), 4.07−4.02 (1H, m, H1), 3.96 (1H, dd, 2 J = J 7′,8 = 7.9 Hz, H7′), 3.84 (3H, s, Me21), 3.66 (1H, dd, 2 J = 7.9 Hz, J 7,8 = 9.0 Hz, H7), 2.49−2.41 (1H, m, H8), 2.26 (1H, sept, J 13,14 = J 13,15 = 6.9 Hz, H13), 2.25−2.16 (1H, m, H9′), 2.12 (1H, dd, 2 J = 17.2 Hz, J 9,8 = 2.7 Hz, H9), 1.13 (3H, s, Me16), 1.01 (3H, d, J 15,13 = 6.9 Hz, Me15), 1.00 (3H, d, J 14,13 = 6.9 Hz, Me14). 13 4.4.12.…”