Reference

Asymmetric epoxidation of cis-alkenes mediated by iminium salts: highly enantioselective synthesis of levcromakalim

Asymmetric epoxidation of cis-alkenes mediated by iminium salts: highly enantioselective synthesis of levcromakalim. Bulman Page, Philip C.; Buckley, Benjamin R.; Heaney, Harry; Blacker, A. John (Department of Chemistry, Loughborough University, Loughborough, Leicestershire LE11 3TU, UK). 33143-29-2 is also in the experiment. Organic Letters, 7(3), 375-377 (English) 2005 American Chemical Society. CODEN: ORLEF7. ISSN: 1523-7060. DOCUMENT TYPE: Journal CA Section: 27 (Heterocyclic Compounds (One Hetero Atom)) Section cross-reference(s): 28 A range of cis-substituted olefins was epoxidized with a new dihydroisoquinolinium salt catalyst, using tetraphenylphosphonium monoperoxysulfate as the stoichiometric oxidant, giving ee's of up to 97%. The reaction has been used as the key step in an enantioselective synthesis of the antihypertensive agent levcromakalim. Thus, (+)-3,4-dihydro-2-[(4S,5S)-4-[4-(methylsulfonyl)phenyl]-2,2-dimethyl-1,3- dioxan-5-yl]isoquinolinium tetrafluoroborate (I) was prepd. in several steps. The epoxidn. of 2,2-dimethyl-2H-1-benzopyran-6-carbonitrile gave (1aS,7bS)-1a,7b-dihydro-2,2-dimethyl-2H-oxireno[c][1]benzopyran-6-c arbonitrile, (II) using I as catalyst and tetraphenylphosphonium peroxymonosulfate as reagent. 33143-29-2 is the cas registry number of certain chemical which is used as reagents here. Further reaction of II with pyrrolidinone gave the title compd., levcromakalim (III). ..

Asymmetric epoxidation of cis-alkenes mediated by iminium salts: highly enantioselective synthesis of levcromakalim

Asymmetric epoxidation of cis-alkenes mediated by iminium salts: highly enantioselective synthesis of levcromakalim. Bulman Page, Philip C.; Buckley, Benjamin R.; Heaney, Harry; Blacker, A. John (Department of Chemistry, Loughborough University, Loughborough, Leicestershire LE11 3TU, UK). 33143-29-2 is also in the experiment. Organic Letters, 7(3), 375-377 (English) 2005 American Chemical Society. CODEN: ORLEF7. ISSN: 1523-7060. DOCUMENT TYPE: Journal CA Section: 27 (Heterocyclic Compounds (One Hetero Atom)) Section cross-reference(s): 28 A range of cis-substituted olefins was epoxidized with a new dihydroisoquinolinium salt catalyst, using tetraphenylphosphonium monoperoxysulfate as the stoichiometric oxidant, giving ee's of up to 97%. The reaction has been used as the key step in an enantioselective synthesis of the antihypertensive agent levcromakalim. Thus, (+)-3,4-dihydro-2-[(4S,5S)-4-[4-(methylsulfonyl)phenyl]-2,2-dimethyl-1,3- dioxan-5-yl]isoquinolinium tetrafluoroborate (I) was prepd. in several steps. The epoxidn. of 2,2-dimethyl-2H-1-benzopyran-6-carbonitrile gave (1aS,7bS)-1a,7b-dihydro-2,2-dimethyl-2H-oxireno[c][1]benzopyran-6-c arbonitrile, (II) using I as catalyst and tetraphenylphosphonium peroxymonosulfate as reagent. 33143-29-2 is the cas registry number of certain chemical which is used as reagents here. Further reaction of II with pyrrolidinone gave the title compd., levcromakalim (III). ..