Synthesis and cytotoxic activity of substituted hexahydro-2H-4,6-(epoxymethano)chromen-8(5H)-ones obtained from (-)-verbenone was written by Il’ina, I. V.;Pokrovsky, M. A.;Mikhalchenko, O. S.;Korchagina, D. V.;Volcho, K. P.;Pokrovsky, A. G.;Salakhutdinov, N. F.. And the article was included in Russian Chemical Bulletin in 2015.Application In Synthesis of 3-Hydroxy-5-methoxybenzaldehyde This article mentions the following:
A number of compounds with a substituted hexahydro-2H-4,6-(epoxymethano)chromen-8(5H)-one framework, I [R1 = R4 = H, R2 = H, OMe, R3 = OMe; R1 = H, R2 = R3 = R4 = OMe; R1 = R2 = R3 = OMe, R4 = H; R1 = H, R2 = R4 = OMe, R3 = OH; R1 = R4 = H, R2 = OH, R3 = OMe; R1 = R4 = H, R2 = OMe, R3 = OH], was synthesized starting from monoterpenoid (-)-verbenone and aromatic aldehydes containing methoxy and hydroxy groups. Cytotoxic activity of these compounds on human tumor cell lines was studied for the first time. Compounds containing three methoxy groups in each aromatic ring were found to be the most promising for further studies. In the experiment, the researchers used many compounds, for example, 3-Hydroxy-5-methoxybenzaldehyde (cas: 57179-35-8Application In Synthesis of 3-Hydroxy-5-methoxybenzaldehyde).
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. But ether is more polar than alkenes. Ethers feature bent C–O–C linkages. In dimethyl ether, the bond angle is 111° and C–O distances are 141 pm. The barrier to rotation about the C–O bonds is low. The bonding of oxygen in ethers, alcohols, and water is similar. In the language of valence bond theory, the hybridization at oxygen is sp3.Application In Synthesis of 3-Hydroxy-5-methoxybenzaldehyde
Referemce:
Ether – Wikipedia,
Ether | (C2H5)2O – PubChem