Rearrangement of Hydroxylated Pinene Derivatives to Fenchone-Type Frameworks: Computational Evidence for Dynamically-Controlled Selectivity
作者:Marcus Blümel、Shota Nagasawa、Katherine Blackford、Stephanie R. Hare、Dean J. Tantillo、Richmond Sarpong
DOI:10.1021/jacs.8b05804
日期:2018.7.25
An acid-catalyzed Prins/semipinacolrearrangementcascade reaction of hydroxylated pinene derivatives that leads to tricyclic fenchone-type scaffolds in very high yields and diastereoselectivity has been developed. Quantum chemical analysis of the selectivity-determining step provides support for the existence of an extremely flat potential energy surface around the transition state structure. This
A Simple, Efficient and General Procedure for Acetalization of Carbonyl Compounds and Deprotection of Acetals under the Catalysis of Indium(III) Chloride
作者:Brindaban C. Ranu、Ranjan Jana、Sampak Samanta
DOI:10.1002/adsc.200303154
日期:2004.3
Indium(III) chloride efficiently catalyzes the protection of a variety of aldehydes and ketones to their corresponding 1,3-dioxolanes and dialkyl acetals in refluxing cyclohexane. On the other hand, deprotection of acetals is also achieved in refluxing aqueous methanol under the catalysis of indium(III) chloride.
Acetals are obtained in good to excellent yields by treatment of aldehydes and ketones with trialkyl orthoformate and the corresponding alcohol in the presence of a catalytic amount of lithium tetrafluoroborate. Due to the mild reaction conditions, this method is compatible with acid-sensitive substrates.