tBuO2H/Cu(acac)2-Mediated Intramolecular Oxidative Lactonization of o-Allyl Arylaldehydes: Synthesis of 1-Oxoisochromans was written by Chang, Meng-Yang;Lai, Kai-Xiang;Chen, Kuan-Ting. And the article was included in Synthesis in 2021.Safety of 3-Hydroxy-5-methoxybenzaldehyde This article mentions the following:
A concise route for tBuO2H/Cu(acac)2-mediated synthesis of 1-oxoisochromans such as I (R = H, Me; R1 = CHO, H, Ac) is described. This includes: (i) oxidation of oxygenated o-allyl arylaldehydes 2-CH(R)CHCH2-3-R2-4-R3-5-R4C6H (R2 = H, OMe, OBn, cyclopentyloxy, etc.; R3 = H, OMe; R4 = H, OMe) and (ii) sequential intramol. lactonization of the resulting olefin-containing benzoic acids. A plausible mechanism is proposed and discussed. In the experiment, the researchers used many compounds, for example, 3-Hydroxy-5-methoxybenzaldehyde (cas: 57179-35-8Safety of 3-Hydroxy-5-methoxybenzaldehyde).
3-Hydroxy-5-methoxybenzaldehyde (cas: 57179-35-8) belongs to ethers. Relative to alcohols, ethers are generally less dense, are less soluble in water, and have lower boiling points. They are relatively unreactive. Autoxidation is the spontaneous oxidation of a compound in air. In the presence of oxygen, ethers slowly autoxidize to form hydroperoxides and dialkyl peroxides. If concentrated or heated, these peroxides may explode. To prevent such explosions, ethers should be obtained in small quantities, kept in tightly sealed containers, and used promptly.Safety of 3-Hydroxy-5-methoxybenzaldehyde
Referemce:
Ether – Wikipedia,
Ether | (C2H5)2O – PubChem