Aldehydes and ketones, including acetophenone and benzophenone, are readily protected under mild, neutral conditions in the presence of various alcohols 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.

中文翻译：

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三氟甲磺酸铟（III）作为温和有效的催化剂，可在存在酸敏感官能团的情况下形成缩醛和缩酮

醛和酮（包括苯乙酮和二苯甲酮）在温和的中性条件下，在各种醇或正甲酸酯和催化量的三氟甲烷磺酸铟（III）（<0.8 mol％）的存在下，在室温或温和的加热条件下均易于保护。相应的环状和非环状缩醛和缩酮，收率良好至极佳。酸敏感的官能团N- Boc，THP和TBDMS在报道的条件下不经历竞争性脱保护。