192054-40-3

Upstream product

• 123-11-5 4-methoxy-benzaldehyde 
• 59983-39-0 (S)-1-amino-2-(methoxymethyl)pyrrolidine 

Downstream Products

• 944128-21-6 (+)-(6R,2S)-1-(2-methoxymethylpyrrolidin-1-yl)-6-(4-methoxyphenyl)piperidin-2-one 
• 944128-16-9 (+)-(6R,2S)-1-(2-methoxymethylpyrrolidin-1-yl)-6-(4-methoxyphenyl)-5,6-dihydro-1H-pyridin-2-one 
• 239116-24-6 (2S)-3-methoxy-1-[(S)-2-(methoxymethyl)pyrrolidin-1-yl]-2-(4-methoxyphenyl)-2,5-dihydro-1H-pyrrole 

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 3-substituted dihydro-2H-isoquinolin-1-ones, dihydro- and tetrahydroisoquinolines via 1,2-addition/ring closure

The asymmetric synthesis of 3-substituted dihydro-2H-isoquinolin-1-ones, dihydro- and tetrahydroisoquinolines is described. The key operation is a tandem 1,2-addition/ring closure sequence employing lithiated ortho-toluamides and aldehyde SAMP- or RAMP-hydrazones as substrates, followed by N-N bond cleavage to remove the auxiliary. Moderate to good yields and high enantiomeric excesses (ee = 85-99%) are reached.

Reaction of the lithio-derivative of methoxyallene with hydrazones. Part 1: Synthesis and transformation of α-allenyl hydrazines

The lithio-derivative of methoxyallene reacts with aldehyde hydrazones leading to expected α-allenyl hydrazines when ether is the solvent of the reaction. The yields are good as well as the diastereoselectivity observed in the case of SAMP-hydrazones. These hydrazines are cleanly transformed to N-dialkylamino-3-methoxy-3-pyrrolines when they are reacted with n-BuLi in THF. These compounds are sometimes accompanied by the isomeric 4-methyl azetidines. The N-dialkylamino-3-methoxy-3-pyrrolines are transformed to 3-methoxy-3-pyrrolines by hydrogenolysis of the nitrogen-nitrogen bond, to 3-alkoxy-pyrroles by treatment with a peracid and to 3-amino-pyrroles by acidic migration of the dialkylamino group. In the case of SAMP-hydrazines, the obtained 3-methoxy-3-pyrrolines have a high enantiomeric purity. Lastly, attempts to prepare α-hydrazino-esters (and subsequently α-amino-esters) by ozonolysis of the allenyl moiety failed due to the formation of a methyl glyoxylate.