Best Synthetic Methods Functional Group Protection

Benzyl esters are easily deprotected by hydrogenolysis. It is often observed, however, as exemplified by the conversion of 1 to 2 reported (Adv. Synth. Catal. 2008, 350, 406) by Hironao Sajiki of Gifu Pharmacutical University, that alkene hydrogenation can be carried out selectively. Fernando Albericio of the University of Barcelona has developed Tetrahedron Lett. 2008,49, 3304) a family of thiophene-based esters 3 that can be removed with acid in the presence of f-butyl esters, and that are stable to the removal of FMOC groups. Vassiliki Theodorou of the University of loannina has found Tetrahedron Lett. 2008, 49, 8230) that esters were rapidly saponified by methanolic NaOH in solvent CH Cl,. 

Dithianes such as 19 have often been deprotected with stoichiometric heavy metals. Andreas Kirschning of Leibniz Universitat Hannover has devised (J. Org. Chem. 2008, 73, 2018) a set of three anionic resins, charged, respectively, with l(OjCCFj)j% HCO, and S Oj. Exposure of 19 to the three resins in secpience deUvered the very sensitive ketone 20. 

Clotilde Ferroud of the Conservatoire National des Arts et Metiers, Paris has established Tetrahedron Lett. 2008, 49, 3004) microwave conditions for the direct acetylation of an amine such as 21 with vinyl acetate 22. Samad Khaksar of the Islamic Azad University, Iran has found Tetrahedron Lett. 2008, 49, 3527) that thiourea 25 catalyzed the protection of an amine 24 with Boc O under similarly mild conditions. Darren J. Dixon of the University of Manchester employed Chem. Commun. 2008, 2474) the protocol developed by Romo to convert the sulfonamide 27 to the trifluoracetate 28. Uno Maeorg of the University of Tartu showed Tetrahedron Lett. 2008, 49, 1373) that sulfonamides can also be deprotected with the inexpensive mischmetal in the presence of TiCl,. 

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Best Synthetic Methods Functional Group Protection... 

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