84646-69-5

Upstream product

• 2065-66-9 methyl-triphenylphosphonium iodide 
• 223694-00-6 di-(-)-menthyl 2-formylcyclopropane-1,1-dicarboxylate 
• 821-06-7 (E)-1,4-dibromobutene 
• 73636-64-3 Malonsaeure-bis<(1R)-menthyl>ester 

Downstream Products

• 50-28-2 estradiol 
• 53-16-7 Estrone 
• 1035-77-4 3-O-methyl-17β-oestradiol 
• 1670-49-1 3-methyl ether of Δ⁹⁽¹¹⁾-dehydroestrone 
• 1624-62-0 estrone 3-methyl ether 
• 80868-73-1 (2S,3S)-2-[3-(4-Methoxy-2-methyl-phenyl)-3-oxo-2-trimethylsilanyl-propyl]-2-methyl-3-vinyl-cyclopentanone 
• 75863-04-6 3-Methoxy-6,7:8,9-diseco-1,3,5⁽¹⁰⁾,7-oestratetraen-11,17-dion 
• 84680-71-7 (2R,3S)-2-[3-(4-Methoxy-2-methyl-phenyl)-3-oxo-propyl]-2-methyl-3-vinyl-cyclopentanone 

Relevant academic research and scientific papers

Chiral synthesis of cyclopropanes. Stereoselective [2 + 1] cycloaddition reactions of 1-seleno-2-silylethenes with di-(-)-menthyl ethene-1,1- dicarboxylates

Reaction of 1-seleno-2-silylethenes 1 with the chiral electrophiles 2, 3, and 4 derived from (-)-menthol, in the presence of zinc halides gave the cyclopropane products 5, 6, and 7, respectively, with high diastereoselectivity. The absolute configuration of 5a, prepared by the reaction of 1-(phenylseleno)-2-(trimethylsilyl)ethene (1a) and di-(-)- menthyl methylenemalonate (2), was determined to be 2S by conversion to the known chiral compound 11. The proposed mechanism, involving fixation of the (-)-menthyl group to the C=C plane by the Lewis acid in the addition step, is consistent with the experimental observations. A selenium-participating secondary orbital interaction in the synclinal addition path was elucidated by ab initio calculations and explained the observed diasteroselectivity.