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Helvetica Chimica Acta – Vol. 98 (2015)
residue was separated repeatedly by CC (SiO2 (4.5 – 20 g); AcOEt/hexane, gradient (0 – 100% and 0 –
35%) as the first eluents and with eluents of constant concentrations (22% for 22 and 24, 17% for 23,
and 21% for 25)) to give (1R,2R,6S)-3-(hydroxymethyl)-6-(prop-1-en-2-yl)cyclohex-3-ene-1,2-diyl
diacetate (22; 126.7 mg, 0.472 mmol, 11.2%), [(1R,4S,5R)-5-(acetyloxy)-6-hydroxy-3,3-dimethyl-2-
oxobicyclo[2.2.1]hept-1-yl]methyl acetate (24; 118.6 mg, 0.442 mmol, 10.4%), [(4S,5R,6R)-5-(acetyl-
oxy)-6-hydroxy-4-(prop-1-en-2-yl)cyclohex-1-en-1-yl]methyl acetate (23; 82.4 mg, 0.307 mmol, 7.3%),
and [(1R,2R,4S,5R)-2-(acetyloxy)-5,6-dihydroxy-3,3-dimethylbicyclo[2.2.1]hept-1-yl]methyl acetate (25;
61.3 mg, 0.228 mmol, 5.4%)). It should be noted that the mixture contained ten unidentified products in
an amount of 1 – 7%.
Data of Compound 23: [a]2D6 ¼ À82.4 (c ¼ 0.153, CHCl3). 1H-NMR (CDCl3): 1.79 (br. s, Me(9)); 1.98,
2
2.06 (2s, Me(12,14)); 2.13 (ddd, J ¼ 18.0, J(5eq, 4) ¼ 5.3, J(5eq, 6ax) ¼ 5.1, HeqÀC(5)); 2.32 – 2.40 (ddm,
2J ¼ 18.0, J(5ax, 6ax) ¼ 11.2, HaxÀC(5)); 2.54 (br. dd, J(6ax, 5ax) ¼ 11.2, J(6ax, 5eq) ¼ 5.1, HÀC(6)); 4.02 (br. s,
2
2
HÀC(2)); 4.54 (d, J ¼ 12.4, 1 H of CH2(10)); 4.69 (br. d, J ¼ 12.4, 1 H of CH2(10)); 4.73 (br. s, 1 H of
CH2(8)); 4.85 – 4.87 (m, all J ꢀ 2.0, 1 H of CH2(8)); 5.19 (dd, J(1eq, 2eq) ¼ 2.8, J(1eq, 6ax) ¼ 2.1, HÀC(1));
6.03 – 6.05 (dm, J(4, 5eq) ¼ 5.3, other J ꢀ 1.5, HÀC(4)). 13C-NMR: 20.82, 20.89 (2q, C(12,14)); 22.20 (q,
C(9)); 25.41 (t, C(5)); 37.96 (d, C(6)); 66.29 (t, C(10)); 66.83 (d, C(2)); 72.45 (d, C(1)); 111.39 (t, C(8));
131.04 (s, C(3)); 131.10 (d, C(4)); 144.39 (s, C(7)); 170.32, 170.92 (2s, C(11,13)). HR-EI-MS: 208.1093
([M À AcOH]þ, C12H16Oþ3 ; calc. 208.1094).
Data of Compound 24: [a]2D4 ¼ À0.39 (c ¼ 1.017, CHCl3). 1H-NMR (CDCl3): 1.10 (s, Me(9)); 1.15 (s,
Me(10)); 2.00, 2.05 (2s, Me(12,14)); 1.98 – 2.07 (m, CH2(7)); 2.54 (ddd, J(4, 5exo) ¼ 4.3, J(4,7) ¼ 2.3, J(4,
7) ¼ 1.7, HÀC(4)); 3.34 (d, J(OH, 6endo) ¼ 2.5, HOÀC(6)); 3.68 (ddd, J(6endo, 5exo) ¼ 3.2, J(6endo, OH) ¼ 2.5,
J(6endo, 7syn) ¼ 2.0, HÀC(6)); 4.33 (d, 2J ¼ 11.6, 1 H of CH2(8)); 4.39 (d, 2J ¼ 11.6, 1 H of CH2(8)); 4.79 (dd,
J(5exo, 4) ¼ 4.3, J(5exo, 6endo) ¼ 3.2, HÀC(5)). 13C-NMR: 20.64, 20.77 (2q, C(12, 14)); 21.63 (q, C(10)); 25.05
(q, C(9)); 31.84 (t, C(7)); 46.75 (d, C(4)); 47.44 (s, C(3)); 59.61 (t, C(8)); 62.17 (s, C(1)); 74.55 (d, C(6));
86.29 (d, C(5)); 170.90, 171.82 (2 s, C(11,13)); 216.77 (s, C(2)). HR-EI-MS: 284.1252 (Mþ, C14H20O6þ ;
calc. 284.1254).
Data of Compound 25: [a]2D6 ¼ À59.9 (c ¼ 0.377, CHCl3). 1H-NMR (CDCl3): 1.01 (s, Me(9)); 1.28 (s,
2
2
Me(10)); 1.58 (ddd, J ¼ 11.1, J(7anti, 2endo) ¼ 1.8, J(7anti, 4) ¼ 1.2, HantiÀC(7)); 1.72 (ddd, J ¼ 11.1, J(7syn
,
6endo) ¼ 2.6, J(7syn, 4) ¼ 2.0, HsynÀC(7)); 2.01, 2.07 (2 s, Me(12,14)); 2.19 (ddd, J(4, 5exo) ¼ 4.2, J(4, 7syn) ¼
2.0, J(4, 7anti) ¼ 1.2, HÀC(4)); 3.63 (ddd, J(6endo, 5exo) ¼ 3.5, J(6endo, OH) ¼ 2.1, J(6endo, 7syn) ¼ 2.6, HÀC(6));
3.75 (d, J(OH, 6endo) ¼ 2.1, HOÀC(6)); 4.04 (d, 2J ¼ 11.5, 1 H of CH2(8)); 4.52 (d, 2J ¼ 11.5, 1 H of
CH2(8)); 4.59 (dd, J(5exo, 4) ¼ 4.2, J(5exo, 6endo) ¼ 3.5, HÀC(5)); 4.73 (d, J(2endo, 7anti) ¼ 1.8, HÀC(2)).
13C-NMR: 20.58, 20.90 (2q, C(12, 14)); 24.01 (q, C(9)); 25.88 (q, C(10)); 33.11 (t, C(7)); 44.47 (s, C(3));
49.29 (d, C(4)); 55.35 (s, C(1)); 60.13 (t, C(8)); 75.06 (d, C(6)); 85.26 (d, C(5)); 89.44 (d, C(2)); 171.46,
171.53 (2s, C(11,13)). HR-EI-MS: 251.1272 ([M À H2O À OH]þ, C14H19O4þ ; calc. 251.1278).
(1R,2R,6S)-3-Formyl-6-(prop-1-en-2-yl)cyclohex-3-ene-1,2-diyl Diacetate (11). CHCl3 was washed
with sat. NaHCO3, dried (CaCl2), and distilled over P2O5. A soln. of 22 (11.8 mg, 44.0 mmol) in CHCl3
(5 ml) was added to a suspension of freshly prepared (as described for the synthesis of 6) MnO2 reagent
(164.8 mg) in CHCl3 (5 ml). The mixture was stirred at r.t. for 6 h. The precipitate was filtered off. The
solvent was distilled off to afford (1R,2R,6S)-3-formyl-6-(prop-1-en-2-yl)cyclohex-3-ene-1,2-diyl diac-
etate (11; 9.2 mg, 34.5 mmol, 78%). [a]D25 ¼ À8.0 (c ¼ 0.25, CHCl3). 1H-NMR (CCl4/CDCl3 1:1): 1.81 (br.
s, Me(9)); 1.96 (s, Me(12)); 2.05 (s, Me(14)); 2.44 (ddd, 2J ¼ 18.0, J(5eq, 6ax) ¼ 5.0, J(5eq, 4) ¼ 5.0,
2
HeqÀC(5)); 2.48 (br. dd, J(6ax, 5ax) ¼ 10.3, J(6ax, 5eq) ¼ 5.0, HÀC(6)); 2.61 (dddd, J ¼ 18.0, J(5ax, 6ax) ¼
10.3, J(5ax, 4) ¼ 2.4, J(5ax, 2eq) ¼ 1.3, HaxÀC(5)); 4.74 (br. s, 1 H of CH2(8)); 4.89 – 4.91 (m, all J ꢀ 2.0,
1 H of CH2(8)); 5.30 (dd, J(1eq, 2eq) ¼ 2.8, J(1eq, 6ax) ¼ 1.3, HÀC(1)); 5.57 (dd, J(2eq, 1eq) ¼ 2.8, J(2eq
,
5ax) ¼ 1.3, HÀC(2)); 7.12 (dd, J(4, 5eq) ¼ 5.0, J(4, 5ax) ¼ 2.4, HÀC(4)); 9.48 (s, HÀC(10)). 13C-NMR: 20.55
(q, C(12)); 20.68 (q, C(14)); 22.33 (q, C(9)); 26.30 (t, C(5)); 39.18 (d, C(6)); 63.50 (d, C(2)); 67.91 (d,
C(1)); 112.04 (t, C(8)); 136.65 (s, C(3)); 143.21 (s, C(7)); 152.62 (d, C(4)); 168.30 (s, C(13)); 168.53 (s,
C(11)); 190.78 (d, C(10)). HR-EI-MS: 164.0829 ([M À AcOH À Ac]þ, C10H12O2þ ; calc. 164.0832).
(1R,2R,6S)-3-(1,3-Dioxolan-2-yl)-6-(prop-1-en-2-yl)cyclohex-3-ene-1,2-diyl Diacetate (28). Ben-
zene was dried by azeotropic distillation. HOCH2CH2OH (27.6 mg, 0.444 mmol), tartaric acid (6.8 mg,
45.3 mmol), and MgSO4 (102.4 mg, 0.85 mmol) were added to a soln. of 11 (23.1 mg, 86.7 mmol) in anh.
benzene (8 ml). The mixture was heated under reflux for 10 h and was left at r.t. for 24 h. Then, it was