Gregg, Brian T.;Golden, Kathryn C.;Quinn, John F. published 《Indium(III)trifluoromethanesulfonate as a mild, efficient catalyst for the formation of acetals and ketals in the presence of acid sensitive functional groups》 in 2008. The article was appeared in 《Tetrahedron》. They have made some progress in their research.Category: ethers-buliding-blocks The article mentions the following:
Aldehydes and ketones, including acetophenone and benzophenone, are readily protected under mild, neutral conditions in the presence of various alcs. or orthoformates and catalytic amounts of indium(III) trifluoromethanesulfonate (<0.8 mol %) under either room temperature or mild heating conditions to give the corresponding cyclic and acyclic acetals and ketals in good to excellent yields. Acid sensitive functional groups, N-Boc, THP, and TBDMS do not undergo competitive deprotection under the reported conditions. The experimental procedure involved many compounds, such as Dimethoxydiphenylmethane (cas: 2235-01-0) .
Dimethoxydiphenylmethane is one of ethers-buliding-blocks. 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. Category: ethers-buliding-blocks The bonding of oxygen in ethers, alcohols, and water is similar. In the language of valence bond theory, the hybridization at oxygen is sp3.
Reference:
Ether – Wikipedia,
Ether | (C2H5)2O – PubChem