19641-15-7

Upstream product

• 67-56-1 methanol 
• 19742-05-3 (2R)-(-)-threo-cis-dihydropalustramic acid 
• 207602-24-2 methyl 2-((2S,6S)-6-((S)-1-hydroxypropyl)-1,2,5,6-tetrahydropyridin-2-yl)acetate 
• 215871-43-5 [(2S,6S)-6-((S)-1-Methoxymethoxy-propyl)-1,2,5,6-tetrahydro-pyridin-2-yl]-acetic acid methyl ester 
• 215871-35-5 (2S,6S)-2-((S)-1-Methoxymethoxy-propyl)-6-(2-triisopropylsilanyloxy-ethyl)-1,2,3,6-tetrahydro-pyridine 
• 215871-27-5 (2S,6S)-1-Benzyl-6-(2-triisopropylsilanyloxy-ethyl)-1,2,3,6-tetrahydro-pyridine-2-carbaldehyde 
• 215871-26-4 [(2S,6S)-1-Benzyl-6-(2-triisopropylsilanyloxy-ethyl)-1,2,3,6-tetrahydro-pyridin-2-yl]-methanol 
• 215871-36-6 (2S,6S)-6-(2-Hydroxy-ethyl)-2-((S)-1-methoxymethoxy-propyl)-3,6-dihydro-2H-pyridine-1-carboxylic acid 2,2,2-trichloro-ethyl ester 
• 215871-40-2 (2S,6S)-1-Benzyl-6-(2-triisopropylsilanyloxy-ethyl)-1,2,3,6-tetrahydro-pyridine-2-carboxylic acid 
• 215871-32-2 (2S,6S)-1-Benzyl-6-(2-triisopropylsilanyloxy-ethyl)-1,2,3,6-tetrahydro-pyridine-2-carboxylic acid methoxy-methyl-amide 
• 215871-34-4 (2S,6S)-1-Benzyl-2-((S)-1-methoxymethoxy-propyl)-6-(2-triisopropylsilanyloxy-ethyl)-1,2,3,6-tetrahydro-pyridine 

Relevant academic research and scientific papers

Stereoselective addition of Grignard reagents to sulfinimines derived from tartrate diol (threitol): Generation of chiral building blocks for the collective total synthesis of lentiginosine, conhydrine and methyldihydropalustramate

A systematic investigation of the addition of Grignard reagents to sulfinimines derived from tartaric acid diol was undertaken. It was observed that the chirality of the inherent tartrate moiety influences the diastereoselectivity of the resultant sulfinamides formed in the reaction. The formed products serve as excellent building blocks for the synthesis of natural products. This has been demonstrated in the collective total synthesis of lentiginosine, (+)-α-conhydrine and methyldihydropalustramate.

Studies toward the synthesis of (+)-palustrine: The first asymmetric synthesis of (-)-methyl palustramate

The stereoselective synthesis of (-)-methyl palustramate, a possible intermediate for the synthesis of (+)-palustrine, is described. The key step of the synthesis is a conformationally restricted Claisen rearrangement to afford the highly functionalized 1-benzylpipecolic ester 10. In addition, a new procedure for debenzylation of 1-benzylpiperidines (Li, NH2CH2)2, Et3N, THF) was used to remove the benzyl protecting group where traditional methods failed.

Tandem Beckmann and Huisgen-White rearrangement as an alternative to the Baeyer-Villiger oxidation of the bicyclo[3.3.1]nonane system: First asymmetric synthesis of (-)-dihydropalustramic acid. X-Ray molecular structure of 2β-ethyl-9-phenylsulfonyl-9-azabicyclo[3.3.1]nonan-3-one

The transformation of the 'fork head ketone' 3b into the corresponding bicyclic lactone 13 via the Beckmann followed by the Huisgen-White rearrangement is described. Application of the method to a homochiral 2-ethyl-substituted bicyclic ketone (+)-3dα gave efficiently (-)-dihydropalustramic acid (-)-2a, a degradation product from the alkaloid palustrine 1, in good optical yield.

THE TANDEM BECKMANN AND HUISGEN-WHITE REARRANGEMENT AS AN ALTERNATIVE TO THE BAEYER-VILLIGER OXIDATION OF THE 9-AZABICYCLONONAN-3-ONE SYSTEM: A FACILE ROUTE TO (+/-)-DIHYDROPALUSTRAMIC ACID

The transformation of the "fork head ketone" (1) into the corresponding bicyclic lactone (4) via the Beckmann followed by the Huisgen-White Rearrangement is described.An α-ethyl-substituted bicyclic ketone (5) was converted efficiently to dihydropalustram