Stereoselective Synthesis of Two New Trihydroxylated Pyrrolidines Using a Meyer–Schuster Rearrangement

Abstract

The synthesis of two new trihydroxylated pyrrolidines, in a highly diastereoselective manner, has been developed using the Meyer-Schuster rearrangement as a key step.

Applications and Limitations of the I2-Mediated Carbamate Annulation for the Synthesis of Piperidines: Five- versus Six-Membered Ring Formation

“…The enantiomer of 34 has been prepared once previously. 28 Comparison of NMR data showed minor differences in the chemical shifts, which can be explained by the use of a different solvent and differences in pH (34 was treated with conc. DCl to ensure that the amine was fully protonated).…”

“…Pyrrolidine 30 was then treated with NaOH in EtOH, which resulted in the smooth hydrolysis of the carbamate and allowed for the synthesis of the previously undisclosed trihydroxylated pyrrolidine 34 in 5–15% yield over five steps. The enantiomer of 34 has been prepared once previously . Comparison of NMR data showed minor differences in the chemical shifts, which can be explained by the use of a different solvent and differences in pH ( 34 was treated with conc.…”

Recent Developments in the Meyer‐Schuster Rearrangement

“…In the field of alkaloids, the MSR has been employed for the preparation of pyrrolidines which are structurally related to polyhydroxylated derivatives, known in particular as glycosidases inhibitors (Scheme 58). [114] Addition of TMS acetylene anion on enantiopure imide 236 gave, after desilylation, the propargylic alcohol 237 as a 6 : 4 mixture of diastereoisomers. MSR was successfully performed using BF 3 .OEt 2 11 in dichloromethane affording 238 as a pure E ‐isomer in excellent yield.…”