Natural stilbenes. V. Synthesis of pinosylvin monomethyl ether was written by Spath, Ernst;Kromp, Kurt. And the article was included in Berichte der Deutschen Chemischen Gesellschaft [Abteilung] B: Abhandlungen in 1941.COA of Formula: C8H8O3 This article mentions the following:
The difficulties encountered in digesting pine heartwood with tech. sulfite liquor unless the wood has previously been extracted with alc. or acetone are apparently due to the presence in the wood of acetone-soluble hindering substances. Erdtman (C. A. 33, 7098.5) has isolated 2 such substances in about 0.8% yield (based on the dry wood), viz. pinosylvin (I) and its mono-Me ether (II). In the course of their work on the natural stilbenes, S. and his coworkers had already synthesized I (see part IV), and in the present paper they describe the synthesis of II. 3,5-HO(MeO)C6H3CO2H, m. 203-4°, was obtained in 10.1-g. yield from 27.8 g. (HO)2C6H3CO2H in 50 cc. MeOH allowed to stand 14 hrs. at 20° with 127 cc. of a solution of 3 g. Na in 100 cc. absolute MeOH and 15.7 cc. Me2SO4, then heated 1.5 hrs. on the water bath. Boiled 2 hrs. with AcCl, evaporated and poured into water, it gave 90% of the 3-acetoxy acid, m. 151.5-2.5°, which with boiling SOCl2 yielded 85% of 3-acetoxy-5-methoxybenzoyl chloride, b. 90-100° (air bath) under 1 Torr; this, reduced in xylene with Pd-BaSO4 and a moderately rapid current of H until the evolution of HCl ceased (4 hrs.), gave, through the NaHSO3 compound, 60% of 3,5-HO(MeO)C6H3CHO (III), sublimes 110-20° (air bath) under 0.02 Torr, m. 130-1°. Condensation of 2 g. III with 2.08 g. PhCH2CO2Na and 12.5 cc. Ac2O by heating 8 hrs. at 160° gave an oily product which was allowed to stand 12 hrs. at 20° under N with 165 cc. of 3% KOH and finally boiled 15 min. The solution, filtered from an insoluble resinous product, made faintly acid and allowed to stand 12 hrs., yielded 55% of 3′-hydroxy-5′-methoxy-α-stilbenecarboxylic acid (IV), m. 200-1°. The resinous product obtained along with IV was again boiled 1 hr. in 3% KOH, acidified and extracted with ether, yielding a cis-trans isomer (V) of IV, m. 181-2°, and depressing the m. p. of IV to 165-74°. When IV was decarboxylated by heating 4 min. at 220° with Naturkupfer C in quinoline and the resulting oil was repeatedly fractionated in a high vacuum at about 140° (air bath) no crystalline product could be obtained. After various unsuccessful attempts to convert it into a crystalline isomer, the desired isomerization was effected by heating the oil in an evacuated bomb 2.5 min. at 350°. The rearranged product (0.666 g. from 1 g. IV) b. 140° (air bath) under 0.02 Torr and, when seeded in benzene with natural II, gave 67% crystalline II, m. 121.5-2.5°, which did not depress the m. p. of natural II. V (0.05 g.) similarly decarboxylated gave 0.026 g. II. In the experiment, the researchers used many compounds, for example, 3-Hydroxy-5-methoxybenzaldehyde (cas: 57179-35-8COA of Formula: C8H8O3).
3-Hydroxy-5-methoxybenzaldehyde (cas: 57179-35-8) belongs to ethers. Ether is less polar than esters, alcohols or amines because of the oxygen atom that is unable to participate in hydrogen bonding due to the presence of bulky alkyl groups on both sides of the oxygen atom. At room temperature, ethers are pleasant-smelling colourless liquids. Relative to alcohols, ethers are generally less dense, are less soluble in water, and have lower boiling points. They are relatively unreactive, and as a result they are useful as solvents for fats, oils, waxes, perfumes, resins, dyes, gums, and hydrocarbons. Vapours of certain ethers are used as insecticides, miticides, and fumigants for soil.COA of Formula: C8H8O3
Referemce:
Ether – Wikipedia,
Ether | (C2H5)2O – PubChem