Triethylsilane → 2',3',5,6-tetrahydrospiro[benzo[1,2-b:5,4-b']difuran-3,8'-[1,4]dioxino[2,3-f]indol]-7'(6'H)-one

Participants

Reaction Steps

To a solution of 6′-(diphenylmethyl)-2′,3′,5,6-tetrahydrospiro[benzo[1,2-b:5,4-b′]difuran-3,8′-[1,4]dioxino[2,3-f]indol]-7′(6′H)-one (0.5 g, 1.0 mmol) in trifluoroacetic acid (7 mL) was added triethylsilane (0.47 mL, 3.0 mmol). The reaction mixture was heated at reflux for 3.5 h and concentrated in vacuo. The residue was triturated in methanol to afford 2′,3′,5,6-tetrahydrospiro[benzo[1,2-b:5,4-b′]difuran-3,8′-[1,4]dioxino[2,3-f]indol]-7′(6′H)-one (0.076 g, 23%) as a colorless solid: mp>250° C.; 1H NMR (300 MHz, DMSO-d6) δ 10.30 (s, 1H), 6.61 (s, 1H), 6.50 (s, 1H), 6.40 (s, 1H), 6.36 (s, 1H), 4.66 (ABq, J=36.8, 9.2 Hz, 2H), 4.54-4.44 (m, 2H), 4.24-4.11 (m, 4H), 3.02-2.92 (m, 2H); 13C NMR (75 MHz, CDCl3) δ 178.8, 160.8, 160.4, 143.3, 138.7, 135.4, 125.1, 120.9, 119.5, 118.9, 113.0, 99.0, 92.2, 79.7, 72.0, 64.2, 63.7, 57.1, 28.3; MS (ES+) m/z 337.9 (M+1).

Provenance & Evidence