Efficient preparation of (1′R)-(−)-1-(2′-hydroxy-1′-phenylethyl)piperidin-2-one: synthesis of (2′S,3R)-(+)-stenusine

Synthesis of carboxylic amides by ring-opening of oxazolidinones with Grignard reagents

“…Insight into the mechanism of the reaction was obtained by studying the related crotyl (but-2-enyl) magnesium bromide as the nucleophile. 16,17 Scheme 6 Formal synthesis of (−)-coniine. These products represent addition of the allyl unit at the c-position.…”

Regioselective Endocyclic Oxidation of Enantiopure 3‐Alkylpiperidines: Synthesis of (3S,5S)‐(‐)‐3‐Ethyl‐5‐Methylpiperidine

“…[7] Now, we report on the regioselective endocyclic oxidation of 1(a -c). The oxidation of these compounds with bromine in the presence of acetic acid generated the regioisomeric mixture 2(a-c) þ 3(a-c) (Scheme 2) in 95% overall yield in different proportions (determined by 1 H NMR from crude reactions).…”

“…[7] (1 0 R,3S)-(-)-1-(2 0 -Hydroxy-1 0 -phenylethyl)-3-methylpiperidin-2-one (2a T ¼ 296(1) K using Mo-K a radiation (l ¼ 0.71073 Å , Bruker P4 diffractometer), corresponding to 2u max ¼ 52.58. 3030 independent reflections (R int ¼ 0.0216) were used for the refinement of 350 parameters, without neither restraints nor constraints (SHELXTL 5.10 package).…”

“…[1 -6] In this context, we previously reported a facile procedure to prepare enantiopure piperidine I and its transformation into II. Then, starting from this compound, the enantioselective synthesis of (2 0 S,3R)-(þ)-stenusine III was achieved in 70% overall yield [7] (Scheme 1).…”

A Concise Stereoselective Synthesis of (R)‐2‐Benzylmorpholine and ML398 from (R)‐(−)‐2‐Phenylglycinol

“…Therefore, the development of new efficient oxidation methods for the preparation of morpholin‐3‐one is highly desirable. In this context, we have reported an efficient endocyclic oxidation of phenylglycinol‐derived piperidine to generate the corresponding piperidin‐2‐one . Thus, the piperidin‐2‐one was a key intermediate in the enantioselective synthesis of (2′ S ,3 R )‐(+)‐stenusine (a, Scheme ).…”