18 Sugiresinol及びHydroxysugiresinolの構造
詳細
New phenolic compounds, named sugiresinol (I) and hydroxysugiresinol (II), were isolated from the heart wood of Cryptomeria japonica D. Don. The structure of sugiresinol (I) was established on the following experimental basis: (i) Hydrogenolysis product (VII) of dimethylether (VI) was treated with HIO_4 to give formaldehyde and aldehyde (VIII). (ii) Dimethylether (VI) was oxidized with chromic acid to furnish anisic acid (X), 4,4'-dimethoxychalcone (XI) and α-(p-methoxyphenyl)-Δ^<α,β>-butenolide (XII). In NMR spectrum of triacetate (V), triplet centered at 6.57τ (J=10.5 cps) is assigned to the axial C_6 proton. Both protons at C_3 and C_4 yieled broad signals at 4.65-5.15τ(half-band width 26 cps) and at 6.85-7.25τ(half-band width 20 cps) respectively. This, as it is known, proves the axial position of both C_3-H and C_4-H. Thus, sugiresinol is represented as (XIV). NMR spectra of (XV) and (V) (Table I and II) show that hydroxysugiresinol has the same carbon skeleton as sugiresinol. Trimethylether (XVI) was oxidised with chromic acid to give 4,3,'4'-trimethoxychalcone (XVII). From these results it is evident that hydroxysugiresinol has the structure (II). NMR spectrum of (XV) [C_6-H: 6.58τ,(1H), t. J=10.5 cps; C_3-H: 4.70-5.20τ(1H), br. m. half-band width 26 cps; C_4-H: 6.90-7.30τ (1H), br. m. half-band width 22 cps] bring to light the possibility that the formula (XVIII) represents hydroxysugiresinol.
