(1S,3′S,4′S,5′S,6′R)-3′,4′,5′,6′-tetrahydro-6,6′-bis(hydroxymethyl)-spiro[2-benzofuran-1(3H),2-[2H]pyran]-3′,4′,5′-triol (15)
15 (663 g, 60% from 3) as a white crystal;
mp 193–194 °C; [α]D25 +43.8° (c 1.07, H2O);
1H NMR (400 MHz, CD3OD) δ: 3.46–3.49 (1H, m), 3.63–3.69 (1H, m), 3.75–3.85 (4H, m), 4.64 (2H, s), 5.10 (1H, d, J = 12.5 Hz), 5.15 (1H, d, J = 12.5 Hz), 7.23–7.27 (1H, m), 7.30–7.37 (2H, m);
13C NMR (100 MHz, CD3OD) δ: 62.8, 65.0, 71.9, 73.5, 74.9, 76.2, 76.3, 111.6, 121.8, 121.9, 129.2, 140.2, 141.2, 142.5;
MS (ESI) m/z: 299 [M + H]+; HRMS (ESI) calcd for C14H19O7 [M + H]+299.1125, found 299.1119.
J. Org. Chem., 2016, 81 (5), pp 2148–2153
DOI: 10.1021/acs.joc.5b02734
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KHAJURAHO, MADHYA PRADESH, INDIA