121783-49-1Relevant articles and documents
Stereoselective total synthesis of (-)-nupharamine utilizing an α-chlorosulfide and a sulfinimine for C-C bond formation
Raghavan, Sadagopan,Rajendar, Sheelamanthula
, p. 131 - 137 (2015/12/30)
An efficient stereoselective synthesis of the nuphar alkaloid, (-)-nupharamine, is reported. The key features include the Lewis acid catalyzed reaction of an α-chlorosulfide with a silyl ketene acetal for C-C bond formation, creation of the stereocenter at C2 by a diastereoselective reaction of allyl indium with a sulfinimine and reductive amination for the introduction of the C6 stereocenter of the piperidine ring.
Convergent Synthesis of the Dihydropyran Core Containing the C1-C15 Subunit of Sorangicin A Employing Gold(I)-Catalyzed Cyclization of an Allenic Alcohol
Raghavan, Sadagopan,Nyalata, Satyanarayana
, p. 10698 - 10706 (2016/11/29)
A convergent route to the C1-C15 subunit of sorangicin A is disclosed. The key steps include carbon-carbon bond formation using an α-chloro sulfide, regioselective hydrozirconation of an internal alkyne for the preparation of a trisubstituted iodoalkene, allene formation using the Myers-Movassaghi protocol, stereoselective reduction of allylic and propargylic ketones using Noyori's catalyst, and gold(I)-catalyzed cyclization of a β-hydroxy allene to construct the dihydropyran ring.
Stereoselective synthesis of the C13-C22 fragment of callystatin A by a non-aldol approach
Raghavan, Sadagopan,Rajendar, Sheelamanthula
, p. 5044 - 5053 (2015/05/05)
An efficient synthetic route to the C13-C22 subunit of callystatin A is reported. The key features include diastereoselective alkylation, using Myers auxiliary, for the preparation of the three carbon synthon 7, stereo- and regioselective oxidative vicina
Enantiopure building blocks for the synthesis of 3-methyl-2-alkanols. Diastereoselective methylmetal addition to a chiral 2-methylaldehyde followed by lipase catalysed esterification
Larsson, Michael,Andersson, Jimmy,Liu, Rong,Hoegberg, Hans-Erik
, p. 2907 - 2915 (2007/10/03)
The racemic synthetic building block (2R*,3R*)-3-methyl-4- (phenylsulfanyl)butan-2-ol (2R*,3R*)-2 was obtained in a high diastereomeric ratio [95:5, (2R*,3R*)/(2R*,3S*)-ratio] by Lewis acid catalysed dimethylzinc addition to racemic 2-methyl-3- (phenylsul
Sulfinyl moiety as an internal nucleophile. 1. Efficient stereoselective synthesis of fragment A of cryptophycin 3
Raghavan, Sadagopan,Tony
, p. 5002 - 5005 (2007/10/03)
A novel, efficient, and stereoselective synthesis of fragment A of cryptophycin 3 is disclosed. The key step involves the regio- and stereoselective transformation of an unsaturated ester to a bromohydrin via anchimeric assistance by the sulfinyl group.
Baker's yeast mediated biohydrogenation of sulphur-functionalised methacrolein derivatives. Stereochemical aspects of the reaction and preparation of the two enantiomers of useful C4 bifunctional chiral synthons
Serra, Stefano,Fuganti, Claudio
, p. 2191 - 2196 (2007/10/03)
The baker's yeast mediated reduction of sulphur-functionalised methacroleins 11, 15 and 18 leads to the preparation of the bifunctional methyl branched C4 chiral synthons 6 and 7. The stereochemical aspects of the biohydrogenation have been investigated. Both the oxidation state of sulphur and the isomeric position of the double bond affected the enantioselectivity of the reduction strongly, thus, offering access to the two enantiomeric forms of 6 and 7.
Kinetic resolution of primary 2-methyl-substituted alcohols via Pseudomonas cepacia lipase-catalysed enantioselective acylation
Nordin, Ove,Nguyen, Ba-Vu,Voerde, Carin,Hedenstroem, Erik,Hoegberg, Hans-Erik
, p. 367 - 376 (2007/10/03)
The enantioselectivities of lipases from Pseudomonas cepacia (PFL, Amano PS, etc.) towards a series of primary 2-methyl-substituted alcohols using vinyl acetate as the acyl donor in transesterifications in organic solvents were studied. In terms of enantioselectivity, the best results were found for 3-aryl-2-methylpropan-1-ols with enantiomeric ratios (E-values) over 100 in most cases, whereas other 3-substituted primary 2-methylpropan-1-ols generally displayed lower enantioselectivities: 3-cycloalkyl-2-methylpropan-1-ols (E ≈ 20) and 2-methylalkan-1-ols (E ≈ 10). Moving the aryl group closer or further away from the chiral centre resulted in low enantioselectivities: 2-arylpropan-1-ols (E 10), 2-methyl-4-(2-thienyl)butan-1-ol (E = 12), 2-methyl-5-(2-thienyl)pentan-1-ol (E = 3.2) and 2-methyl-6-(2-thienyl)hexan-1-ol (E = 3.8).
Convergent synthesis of a key intermediate for hypocholesterolemic agent 1233A, starting from methyl 3-hydroxy-2-methylpropanoate and asymmetrized bis(hydroxymethyl)acetaldehyde (BHYMA*)
Guanti, Giuseppe,Banfi, Luca,Schmid, Giovanna
, p. 4239 - 4242 (2007/10/02)
Compound 2, which is a known intermediate for the total synthesis of hypocholesterolemic agent 1233A 1, has been synthesized in good overall yield through a convergent approach, employing 3-hydroxy-2-methylpropanoate 6 and BHYMA* 5 as chiral building bloc
PREPARATION OF CHIRAL C5-BUILDING BLOCKS FOR TERPENE SYNTHESIS BY BAKERS' YEAST REDUCTION OF SULFUR-FUNCTIONALIZED PRENYL DERIVATIVES
Sato, Toshio,Hanayama, Kyoko,Fujisawa, Tamotsu
, p. 2197 - 2200 (2007/10/02)
Enantioselective hydrogenation of several α,β-unsaturated aldehydes and allylic alcohols of sulfur-functionalized prenyl derivatives with bakers' yeast gave bifunctional chiral (S)- and (R)-C5-building blocks for terpene synthesis with high enantiomeric e
