212612-91-4

Upstream product

• 158250-17-0 Benzoic acid (4R,6R)-2-oxy-6-((1S,2R)-2-phenyl-cyclohexyloxy)-5,6-dihydro-4H-[1,2]oxazin-4-yl ester 
• 212612-90-3 (Z)-1-[(dimethyl(1,1,2-trimethylpropyl)silyl)oxy]-4-(dimethylphenylsilyl)-3-buten-2-one 
• 67373-56-2 chlorodimethyl(1,1,2-trimethylpropyl)silane 
• 220496-84-4 (Z)-1,4-bis-(dimethyl(1,1,2-trimethylpropyl)silyloxy)-2-butene 
• 212612-88-9 1-[(dimethyl(1,1,2-trimethylpropyl)silyl)oxy]-4-(dimethylphenylsilyl)-3-butyn-2-ol 
• 212612-89-0 (Z)-1-[(dimethyl(1,1,2-trimethylpropyl)silyl)oxy]-4-(dimethylphenylsilyl)-3-buten-2-ol 
• 212612-95-8 2-[(dimethyl(1,1,2-trimethylpropyl)silyl)oxy]ethanal 
• 17156-64-8 (dimethylphenylsilyl)acetylene 

Downstream Products

• 212612-92-5 (2R,3R,3aR,4R,6R)-4-benzyloxy-2-{(1S)-1-hydroxy-2-[dimethyl(1,1,2-trimethylpropyl)siloxy]ethyl}-3-(dimethylphenylsilyl)-6-[(1S,2R)-(2-phenylcyclohexyl)oxy]hexahydroisoxazolo-[1,7b][1,2]oxazine 
• 212612-93-6 (2R,3R,3aR,4R,6R)-4-benzyloxy-2-{(1S)-2-[dimethyl(1,1,2-trimethylpropyl)siloxy]-1-[(methanesulfonyl)oxy]ethyl}-3-(dimethylphenylsilyl)-6-[(1S,2R)-(2-phenylcyclohexyl)oxy]hexahydroisoxazolo-[1,7b][1,2]oxazine 

Relevant academic research and scientific papers

Synthesis of (-)-7-Epiaustraline and (-)-1-Epicastanospermine

Highly efficient and selective syntheses of the title compounds are described. The cornerstone of the synthetic plan is the tandem inter [4 + 2]/inter [3 + 2] cycloaddition process. These syntheses differ from previous applications of this strategy in that they incorporate an alkylation in the hydrogenolysis step to close the second ring of the azabicyclic systems. Notable features of the sequence are (1) the highly regio- and stereoselective [3 + 2] cycloaddition of nitronate 15 with siloxymethyl (Z)-β-silylvinyl ketone (Z)-22b and (2) the highly selective reduction of the resulting ketone 24a with L-Selectride. A single-crystal X-ray structure analysis of synthetic (-)-7-epiaustraline confirmed that the targeted structure was successfully synthesized. This stimulated a reexamination of the structural assignment of the natural product. (-)-1-Epicastanospermine was synthesized in four steps from the common intermediate 27a. The absolute configuration of (-)-1-epicastanospermine was assured by single-crystal X-ray structure analysis of intermediate (-)-27a. Thus, the sign of the optical rotation had to be revised. The overall efficiency of these syntheses were 9 steps and 23% yield for (-)-7-epiaustraline and 10 steps and 20% yield for (-)-1-epicastanospermine.

Tandem cycloaddition chemistry of nitroalkenes: Preparative and theoretical studies on the stereochemical course of [3 + 2] cycloaddition of cyclic nitronates

Intermolecular [3 + 2] cycloadditions between two cyclic nitronates and a series of dipolarophiles are examined. High facial selectivity is observed in all cases and is analyzed with the aid of ab initio transition structure calculations. Monosubstituted dipolarophiles reacted with exclusive regiocontrol. Disubstituted dipolarophiles reacted with varying degrees of regiocontrol, which was dependent on the substituent. A theoretical approach for predicting regioselectivity is discussed. Exo selectivity was generally favored due to steric effects, and was especially high with cis-disubstituted dipolarophiles.