Trimethylsilyl Trifluoromethanesulfonate (TMSOTf) Assisted Facile Deprotection of N,O-Acetonides

Abstract

Employing TMSOTf as an easily available reagent, we have developed a mild and efficient method for the deprotection of both terminal and internal N,0-acetonide functionalities. Various regularly used protecting groups and common organic functional moieties were found to be unaffected by the described reaction conditions. In a few representative examples, the present method was also extended to deprotect acetonides obtained from 1,2-, and 1,3-terminal diols. The acetonide deprotection protocol described herein is expected to be a useful addition to the presently available methods for performing the above transformation.

A New and Improved Synthesis of the Precursor of the Hypoxia Marker [¹8F]-FMISO

“…A possible mechanistic pathway for the observed acetonide cleavage is proposed and this is based on a previously reported mechanistic proposal for the deprotection of N,O-acetonides with TMSOTf. 17 Tosylation of 11 was subsequently further explored (Scheme 4). A highly efficient procedure for the regioselective tosylation of glycols through an intermediate stannylene acetal has been reported and involves the use of catalytic n-Bu 2 SnO.…”

First Asymmetric Total Synthesis of Penarolide Sulfate A1

“…A biological activity profile of the desulfated penarolide sulfate A 1 (30) was also disclosed. The cornerstone of our synthetic protocol was intramolecular Sonogashira cross-coupling reaction for the construction of the key 30-membered macrocyclic ring.…”

“…Following our earlier method of sulfation, compound 31 afforded a number of products that we failed First Asymmetric Total Synthesis of Penarolide Sulfate A 1 Figure 2. TMSOTf [30] mediated opening of the isopropylidene group also failed to furnish desired product 32. (A) The sigmoidal curve indicates the best fit for the percentage inhibition data obtained, and the IC 50 value was calculated from the graph.…”

“…Synthesis of desulfated penarolide sulfate A 1 (30). Synthesis of desulfated penarolide sulfate A 1 (30).…”

Cyclic Sulfamidite as Simultaneous Protecting Group for Amino Alcohols: Development of a Mild Deprotection Protocol Using Thiophenol

“…[1][2][3][4] Therefore, great efforts have been made by several synthetic chemists to develop a variety of synthetic methods for amino alcohols. [5][6][7][8][9] In sharp contrast, the choice of protecting group for the amino alcohols, particularly in terms of simultaneous protecting groups for 1,2-and 1,3-amino alcohols, is limited to two types only [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24] (Chart 1). The most frequently used type is isopropylidene N-O acetal (acetonide), the introductions and removals of which are generally performed under acidic conditions [12][13][14][15] (Chart 1a).…”