Trichloroboron‐promoted Deprotection of Phenolic Benzyl Ether Using Pentamethylbenzene as a Non Lewis‐Basic Cation Scavenger

Abstract This article determined that a combination of BCl3 and pentamethylbenzene (C6HMe5) facilitated smooth debenzylation even at −78 °C by modifying Yoshino's conditions using TFA and C6HMe5. Kobayashi and co‐workers applied the conditions to remove aliphatic benzyl ethers by replacing BCl3 with BBr3.11 Acid‐labile and easily reduced triene remained intact under the conditions to provide the corresponding pentaol in 59% yield.