432042-89-2

Upstream product

• 24424-99-5 di-tert-butyl dicarbonate 
• 1033598-98-9 (2S)-1-amino-4-phenylbutan-2-ol 
• 1308373-10-5 C₂₂H₂₉NO₃ 
• 1308373-09-2 C₁₇H₂₁NO 
• 1308373-08-1 C₂₇H₂₇NO₂ 
• 1308373-07-0 C₂₇H₂₃NO₂ 
• 1308372-87-3 C₂₀H₁₇NO₂ 
• 85290-51-3 (S)-1-nitro-4-phenyl-2-butanol 
• 104-53-0 3-phenyl-propionaldehyde 

Relevant academic research and scientific papers

Kinetic resolution of the racemic 1-(aryloxazol-2-YL)carbinols with achiral carboxylic acids by asymmetric esterification: A new method for the preparation of chiral 1,2-amino alcohols

An efficient kinetic resolution of racemic 1-(aryloxazol-2-yl)carbinols with achiral carboxylic acids using pivalic anhydride in the presence of (R)-benzotetramisole ((R)-BTM) is reported. It was determined that the naphth[1,2-d]oxazole moiety at the C-1 position in the alcohols is a suitable structure to attain a high selectivity. An application to produce optically pure 1,2-amino alcohols was developed by the kinetic resolution of the racemic 1-(aryloxazol-2-yl)carbinols followed by a two-step cleavage of the aryloxazole part to form the corresponding amino group. Transition states that provide the desired (R)-esters from (R)-1-(benzoxazol-2-yl)ethan-1-ol or the undesired (S)-esters from (S)-1-(benzoxazol-2-yl)ethan-1-ol are disclosed by DFT calculations. Another transition state that affords the desired (R)-ester from (R)-1-(naphth[1,2-d]oxazol-2-yl)ethan-1-ol included in the racemic mixture is also estimated, and the structural features of these transition states are discussed. The Japan Institute of Heterocyclic Chemistry.

1,2-oxazines as building blocks for stereoselective synthesis: Preparation of oxygen-substituted 1,2-oxazines, either by alcohol addition or by epoxidation, and subsequent hydrogenation leading to 1,2-amino alcohols and pyrrolidines

Stereodefined oxygen-substituted 1, 2-oxazines were prepared by three different routes. The cycloaddition of enol ethers such as 1 with a-nitrosoalkenes generated in situ gave the heterocycles 3 and 4. Acid-catalysed additions of alcohols to the 6H-1, 2-oxazines 5 led to mixtures of the adducts 6 and the substitution products 7 with moderate chemoselectivity. Epoxidation of the 6H-1, 2-oxazines 5 proceeded more efficiently and furnished the corresponding epoxides 25 and 32 in reasonable to excellent yields. It was demonstrated that the resulting oxygen-substituted 1, 2-oxazines were suitable precursors for the preparation of cyclic or acyclic primary and secondary amines in racemic or enantiopure form. Hydrogenation of the 3-phenyl-substituted 1, 2-oxazines 3 and 25a and of (6S)- and (6R)-32 preferentially furnished the 1, 2amino alcohols 15, rac-29 and (2S)- and (2R)-29. On the other hand, reduction of the 3-ethoxycarbonyl-substituted 1, 2-oxazines 4, 6d and 20 led to the formation of the N-protected proline esters 21-24 in moderate yields. It was also found that the 5-methyl-6H-1, 2-oxazine 10 was a good precursor for the propargylic ether 11, which allowed a Pauson-Khand reaction leading to the tricyclic compounds 13 and 14. Hydrogen peroxide converted 10 into a hydroperoxide intermediate, which was further transformed into the l, 2-oxazin-6-one 28b. Overall, the results demonstrate the remarkable potential of suitably substituted 1, 2-oxazine derivatives for the stereoselective synthesis of amines.