| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1346730 | Tetrahedron: Asymmetry | 2015 | 8 Pages |
A stereoselective and enantiodivergent strategy for the construction of δ-lactams is described. The strategy utilizes chiral malonic esters prepared from enantiomerically enriched mono esters of disubstituted malonic acid. A cyclization occurs with the selective displacement of a substituted benzyl alcohol as the leaving group. The resulting δ-lactams are then converted into nipecotic acid analogues using straightforward transformations. The resulting nipecotic acid analogues proved capable organocatalysts in Mannich reactions.
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(R)-5-(1,3-Dioxoisoindolin-2-yl)-2-(ethoxycarbonyl)-2-methylpentanoic acidC17H19NO6[α]D24 = +5.8 (c 2, MeOH)Source of chirality: EnzymaticAbsolute configuration: (R)
(S)-1-Ethyl 3-(4-nitrobenzyl) 2-(3-(1,3-dioxoisoindolin-2-yl)propyl)-2-methylmalonateC24H24N2O8[α]D23 = −33 (c 1, CH2Cl2)Source of chirality: the precursorAbsolute configuration: (S)
(R)-Ethyl 3-methyl-2-oxopiperidine-3-carboxylateC9H15NO3[α]D24 = +29.2 (c 1, CH2Cl2)Source of chirality: the precursorAbsolute configuration: (R)
(R)-Ethyl 1-benzyl-3-methyl-2-oxopiperidine-3-carboxylateC16H21NO3[α]D24 = +62.6 (c 2, CH2Cl2)Source of chirality: the precursorAbsolute configuration: (R)
(S)-Ethyl 1-benzyl-3-methyl-2-thioxopiperidine-3-carboxylateC16H21NO2S[α]D22 = +75.2 (c 1, CH2Cl2)Source of chirality: the precursorAbsolute configuration: (S)
(R)-Ethyl 1-benzyl-3-methylpiperidine-3-carboxylateC16H23NO2[α]D21 = +11.8 (c 1, CH2Cl2)Source of chirality: the precursorAbsolute configuration: (R)
(R)-1-Benzyl-3-methylpiperidine-3-carboxylic acidC14H19NO2[α]D22 = +19.0 (c 1, MeOH)Source of chirality: the precursorAbsolute configuration: (R)
(R)-3-Methylpiperidine-3-carboxylic acidC7H13NO2[α]D24 = +1.2 (c 1, MeOH)Source of chirality: the precursorAbsolute configuration: (R)
(S)-3-Methylpiperidine-3-carboxylic acidC7H13NO2[α]D21 = −1.5 (c 1, MeOH)Source of chirality: the precursorAbsolute configuration: (S)
(S)-1-tert-Butyl 3-ethyl 2-(3-(1,3-dioxoisoindolin-2-yl)propyl)-2-methylmalonateC21H27NO6[α]D23 = −5.2 (c 1, MeOH)Source of chirality: the precursorAbsolute configuration: (S)
(S)-tert-Butyl 3-methyl-2-oxopiperidine-3-carboxylateC11H19NO3[α]D23 = −16.2 (c 1, CH2Cl2)Source of chirality: the precursorAbsolute configuration: (S)
