227622-64-2

Upstream product

• 61186-66-1 1-methoxyallenyllithium 
• 91190-38-4 N-benzyl-2,3-O-isopropylidene-D-glyceraldehyde nitrone 
• 13169-00-1 Methoxyallene 

Downstream Products

• 444307-92-0 (4aR,7S,7aR)-1-benzyl-4a-methoxyhexahydro-1H-furano[3,2-c][1,2]oxazin-7-ol 
• 1122571-89-4 C₁₄H₁₉NO₄ 
• 1449739-98-3 (4'S)-1-benzyl-2-(2',2'-dimethyl-1',3'-dioxolan-4'-yl)-3-methoxypyrrole 
• 294198-94-0 (E)-(4R,4'S)-4-benzylamino-4-(2',2'-dimethyl-1',3'-dioxolan-4'-yl)-3-methoxybut-2-en-1-ol 
• 1291072-32-6 (1S,2S)-tert-butyl {5'-[1-(benzyl(methyl)amino)-3-(tert-butoxycarbonyloxy)-2-hydroxypropyl]pyrazole}carboxylate 
• 1291072-30-4 (2S,3S)-3-(benzyl(methyl)amino)-3-(2H-pyrazol-3-yl)propane-1,2-diol 
• 1219706-22-5 (1S,5R,6R,4'S)-4-benzyl-7,7-dibromo-5-(2',2'-dimethyl-1',3'-dioxolan-4'-yl)-6-methoxy-3-oxa-4-azabicyclo[4.1.0]heptane 
• 1219706-21-4 (1R,5R,6S,4'S)-4-benzyl-7,7-dibromo-5-(2',2'-dimethyl-1',3'-dioxolan-4'-yl)-6-methoxy-3-oxa-4-azabicyclo[4.1.0]heptane 

Relevant academic research and scientific papers

Stereodivergent syntheses of highly substituted enantiopure 4-alkoxy-3,6-dihydro-2H-1,2-oxazines by addition of lithiated alkoxyallenes to carbohydrate-derived aldonitrones

Additions of lithiated alkoxyallenes to D-glyceraldehyde-based nitrones 1 and 2 did not provide the expected hydroxylamine derivatives. Instead, a novel [3+3] cyclization process furnished 4-alkoxy-3,6-dihydro-2H-1,2-oxazines 9-14 with excellent syn selectivities and in moderate to good yields. Through precomplexation of the nitrones the corresponding anti-configured 1,2-oxazines 9, 10 and 13 could be obtained with high stereoselectivity. The reactions of nitrones 3-6, derived from D-erythrose or D-threose, generally proceeded less diastereoselectively, but reasonable yields of anti-configured 1,2-oxazines such as anti-17 and anti-19 could be obtained under Lewis acid promotion conditions. This was also the case for reactions of the D-arabinose-derived nitrone 7, which provided the anti-1,2-oxazines 23 and 24 with excellent diastereoselectivity and in good yields. Bisnitrone 8 and lithiated methoxyallene furnished a mixture of six compounds, among which the major component was the C2-symmetric syn/syn-1,2-oxazine 29. The diastereoselectivities of these reactions are interpreted on the basis of Dondoni's model for reactions between organolithium compounds and nitrones. The mechanisms for formation of 1,2-oxazines and of side products are discussed. The method introduced here seems to be of broad applicability and an excellent tool for diastereoselective chain elongation of carbohydrate derivatives, affording stereodefined precursors of aminopolyols and other highly functionalized compounds. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005.

A new diastereoselective synthesis of enantiomerically pure 1,2-oxazine derivatives by addition of lithiated methoxyallene to chiral nitrones

Addition of lithiated methoxyallene 2 to nitrones provided hydroxylamine derivatives which usually undergo very fast cyclization to 3,6-dihydro-2H- 1,2-oxazines. Chiral nitrones 5, 8, or 10 which furnished 1,2-oxazines 6, 9, and 11 with excellent syn diastereoselectivities are of particular interest. By precomplexation of nitrone 5b with diethylaluminum chloride 1,2-oxazine 6b was produced with excellent anti selectivity. The resulting 3,6-dihydro-2H- 1,2-oxazines are versatile starting materials for stereoselective syntheses of polyfunctional compounds.