72170-90-2

Upstream product

• 59983-39-0 (S)-1-amino-2-(methoxymethyl)pyrrolidine 
• 123-72-8 butyraldehyde 

Downstream Products

• 825601-07-8 (2R,2S)-(-)-[2-(benzyloxymethyl)butylidene][2-(methoxymethyl)pyrrolidin-1-yl]amine 
• 825601-18-1 (1R,1'R,2S)-(-)-{1-[(1'-benzyloxymethyl)propyl]pentyl}[2-(methoxymethyl)pyrrolidin-1-yl]amine 
• 943987-65-3 [(2S,3S)-5-benzyloxy-3-(tert-butyldimethylsilanyloxy)-2-ethylpent-(E)-ylidene][(R)-2-methoxymethylpyrrolidin-1-yl]amine 

Relevant academic research and scientific papers

Asymmetric synthesis of 6-alkyl- And 6-arylpiperidin-2-ones. Enantioselective synthesis of (S)-(+)-coniine

A variety of diolefinic hydrazides (1) have been assembled in a highly diastereoselective manner by addition of allyllithium to chiral SAMP hydrazones followed by N-acylation with acryloyl chloride. Substrates 1 undergo ring-closing metathesis to give the cyclic enehydrazides (5) which can be easily converted into virtually enantlopure 6-alkyl- or 6-arylpiperidin-2-ones (7). The versatility of this hydrazone addition-RCM protocol has been further exemplified by the conversion of the unsaturated heterocycle 5b into the piperidine alkaloid (S)-(+)-coniine.

Asymmetric synthesis of β-substituted γ-lactams employing the samp-/ramp-hydrazone methodology. Application to the synthesis of (R-(-)-baclofen

A short and efficient asymmetric synthesis of β-substituted γ-lactams is described. Key steps are the α-alkylation of aldehyde SAMP-hydrazones with alkyl bromoacetates, their MMPP mediated conversion to the corresponding nitriles and a reductive cyclization with Raney Ni or Ni boride to the title pyrrolidin-2-ones. The β-substituted γ-lactams are obtained in three steps, good overall yields (27-78%) and excellent enantiomeric excesses (ee=93-99%). The applicability of this procedure for the asymmetric synthesis of GABAs (γ-aminobutyric acids) is demonstrated for (R-(-)-baclofen hydrochloride, which is obtained in 4 steps 55% yield and 94% ee.