186597-30-8

Upstream product

• 115156-56-4 (1R,2S,5R)-5-methyl-2-<1-methyl-1-(benzylamino)ethyl>cyclohexan-1-ol 
• 235094-13-0 1-((2S,4aS,7R,8aR)-4,4,7-Trimethyl-2-phenylselanylmethyl-hexahydro-benzo[e][1,3]oxazin-3-yl)-propenone 
• 235093-64-8 2-(phenylseleno)methylperhydro-1,3-benzoxazine 
• 55179-51-6 (-)-aminomenthol 
• 235093-73-9 (3R,3aS,4aR,6R,8aS)-3,6,9,9-Tetramethyl-decahydro-benzo[e]pyrrolo[2,1-b][1,3]oxazine 
• 235093-85-3 (2R,3aS,4aR,6R,8aS)-2,6,9,9-Tetramethyl-decahydro-benzo[e]pyrrolo[2,1-b][1,3]oxazine 
• 186597-26-2 (2R,3aS,4aR,6R,8aS)-2,6,9,9-Tetramethyl-octahydro-benzo[e]pyrrolo[2,1-b][1,3]oxazin-1-one 
• 235093-81-9 N-allyl-2α-(phenylseleno)methyl-4,4,7α-trimethyl-trans-octahydro-1,3-benzoxazine 
• 235093-66-0 N-(phenylseleno)ethyl-4,4,7α-trimethyl-2α-vinyl-trans-octahydro-1,3-benzoxazine 
• 235093-65-9 N-(phenylseleno)ethyl-8-aminomenthol 
• 203190-41-4 N-allyl-8-aminomenthol 

Downstream Products

• 69498-24-4 (R)-3-methylpyrrolidine 

Relevant academic research and scientific papers

Regio- and stereoselective 5-exo radical cyclizations on a chiral perhydro-1,3-benzoxazine moiety. An access to enantiopure 3-alkylpyrrolidines

Both enantiomers of chiral, nonracemic 3-alkyl-substituted pyrolidines are prepared by diastereo-selective 5-exo-trig cyclization on (-)-8- aminomenthol-derived perhydro-1,3-benzoxazines used as chiral auxiliaries, followed by elimination of the menthol appendage. The diastereoselective radical cyclization is promoted by tributyltin hydride and occurs on a 3- aza-5-hexenyl-type radical, leading to five-membered rings in high yield. The stereocontrol of the cyclization is strongly influenced by 1,3-allylic strain so that an appropriate substitution pattern on the olefin-acceptor and the presence of a vicinal stereocenter are crucial for achieving good diastereoselectivity. The enantiopure pyrrolidines are obtained in three steps with concomitant recovering of the starting (+)-pulegone auxiliary.

A novel approach to chiral, nonracemic pyrrolidines by 5-exo-trig diastereoselective radical cyclization on acrylamides derived from (-)-8- aminomenthol

α,β-Unsaturated amides supported on perhydro-1,3-benzoxazines derived from (-)-8-aminomenthol as chiral auxiliaries undergo regio- and stereoselective 5-exo-trig radical cyclization leading to diastereomeric five-membered lactams. These cyclization products are transformed into enantiopure 3,4-disubstituted pyrrolidines by reduction with aluminum hydride followed by removal of the menthol appendage.

Diastereoselective 5-exo-trig radical cyclisation on N-acryloyl-tetrahydro-1,3-oxazines. A novel approach to enantiopure 3-substituted pyrrolidines

N-acryloyl-2-(phenylselenomethyl)-tetrahydro-1,3-oxazine 1 generates a carbon-centred radical in the presence of tri-n-butyltin hydride and AIBN. This radical underwent diastereoselective 5-exo-trig cyclisation leading to a mixture of five-membered lactams 2a and 2b (d.e. 68%). Chromatographic separation of the diastereomers and elimination of the chiral auxiliary provided enantiopure (R)-3-methylpyrrolidine in good chemical yield. Copyright (C) 1996 Elsevier Science Ltd.