N,S-dimethyl-s-phenylsulfoximine

The Julia Reaction

“…Unfortunately, coupling between optically pure a-lithiated sulfoximines and aldehydes or ketones generally leads to 1:1 mixtures of syn/anti adducts [156,[158][159][160][161]. Despite this shortcoming, chiral sulfoximines have found widespread application in a number of useful synthetic transformations, including resolution [162][163][164][165][166][167][168][169][170][171][172][173][174].…”

Total Synthesis of (–)‐13‐Acetoxymodhephene and (+)‐14‐Acetoxymodhephene

“…Therefore, 21aЈ was used for asymmetric induction and the optical purity was further improved by eliminating undesired enantiomer 22aЈ through the formation of chiral sulfoximine of 22aЈ. [16] An alternative route to introduce the C-5 quaternary center was also explored, as the cinchona alkaloid catalyzed alkylation of 24 was reported to produce 9 with high enantioselectivity. The enantioselective conjugate addition reaction of tert-butyl 2-oxocyclopentane carboxylate (24) to acrolein by using quinidine-based organocatalyst 23 provided 9 with 93 % ee.…”

“…The sulfoximine adduct of 8 was separable from other diastereomers, and hydrolysis of the sulfoximine regenerated pure 8. [16] Stereoselective functionalization of enone 8 to epoxyketones 6 and 7 was one of the crucial steps in the total synthesis. However, an earlier observation from the total synthesis of modhephene from racemic 8 was not promising, as the cyanide addition reaction proceeded with low selectivity, resulting in a 2.5:1 diastereomeric ratio of the 1,4-addition products.…”

Progress in the Synthesis of Guanacastepenes

“…After resolution applying Johnson sulfoximine methodology [20] and formation of the corresponding oximes 50, alkene 43 was obtained in its two enantiomerically enriched forms by Beckman fragmentation (one configuration is shown). After resolution applying Johnson sulfoximine methodology [20] and formation of the corresponding oximes 50, alkene 43 was obtained in its two enantiomerically enriched forms by Beckman fragmentation (one configuration is shown).…”