PMID-sentid Pub_year Sent_text comp_official_name comp_offsetprotein_name organism prot_offset 31720519-7 2019 Why one syn adduct is obtained with aldehydes, whereas cyclic ketones (the predicted ring-fused cyclobutanes of which isomerize to their enamines more easily) produce the other syn adduct, is also explained by means of molecular orbital calculations. Ketones 55-69 synemin Homo sapiens 177-180 10864760-2 2000 The so-formed syn-alpha-methyl-beta-hydroxy amides were transformed into other valuable chiral nonracemic synthons such as alpha-methyl-beta-hydroxyacids, esters, and ketones. Ketones 167-174 synemin Homo sapiens 14-17 10732972-2 2000 The amino-allocolchicinoid (9), a key compound in this study, was transformed to the highly potent ketone 10 and by oxidation with H2O2/Na2WO4 to a mixture of syn/anti-oximes, like 11 and 12. Ketones 99-105 synemin Homo sapiens 159-162 10813959-1 2000 The reaction of alpha-sulfinyl carbanions, derived from the beta-silylethyl sulfoxides, with ketones or trimethyl phosphate, gave the syn products with high stereoselectivity. Ketones 93-100 synemin Homo sapiens 134-137 15045231-0 1996 Syn/anti isomerization of 2,4-dinitrophenylhydrazones in the determination of airborne unsymmetrical aldehydes and ketones using 2,4-dinitrophenylhydrazine derivation. Ketones 115-122 synemin Homo sapiens 0-3 26485576-2 2015 Bicyclic alpha,beta-unsaturated lactams in which the aminal is derived from a ketone have been found to afford products of syn conjugate addition. Ketones 78-84 synemin Homo sapiens 123-126 26781998-1 2016 The synthesis of new enantiopure syn- and anti-3-(alpha-aminobenzyl)-benzo-gamma-sultam ligands 6 and their application in the ruthenium(ii)-catalyzed asymmetric transfer hydrogenation (ATH) of ketones using formic acid/triethylamine is described. Ketones 194-201 synemin Homo sapiens 4-7 25014710-1 2014 The first asymmetric gamma-alkoxyallylboration of representative ketones provides beta-alkoxy tert-homoallylic alcohols 10 whose diastereoselectivities range from 99% syn (acetophenone) to 99% anti (pinacolone) both with high ee (>95%). Ketones 65-72 synemin Homo sapiens 167-170 26301563-3 2015 Application of unsaturated aldehydes and ketones in the second step of the iterative sequence allows the construction of cyclic syn-ketols and acyclic compounds with multiple contiguous stereocenters. Ketones 41-48 synemin Homo sapiens 128-131 26138361-2 2015 This process allows syn substituents to be established stereospecifically on the 2-carbon bridge connecting the ketone carbonyl carbons, and the formation of one carbon-carbon and two carbon-oxygen bonds. Ketones 112-118 synemin Homo sapiens 20-23 20355742-1 2010 syn-Tertiary homoallylic alcohols were obtained by the reaction of alpha-silylallenyltitanocenes generated by the reductive titanation of gamma-silylpropargylic carbonates with Cp(2)Ti[P(OEt)(3)](2) with ketones and following desilylation and partial hydrogenation. Ketones 204-211 synemin Homo sapiens 0-3 24113062-2 2013 Structure-activity data generated from both syn- and anti-aldol precursors provides significant insights into the requirements for enhanced potency, validating this novel ketone-to-aryl halide bioisostere hypothesis. Ketones 171-177 synemin Homo sapiens 44-47 21958056-1 2011 Proline anthranilamide-based pseudopeptides were shown to be effective organocatalysts for enantioselective direct aldol reactions of a selection of aldehydes with various ketones with excellent yield, enantioselectivity up to 99% and anti to syn diastereoselectivity up to 25:1. Ketones 172-179 synemin Homo sapiens 243-246 20942379-4 2010 The E- and Z-crotyl reagents react diastereoselectively with aldehydes and ketones to produce anti and syn adducts, respectively, a result consistent with a cyclic transition state (type I mechanism). Ketones 75-82 synemin Homo sapiens 103-106 24499418-3 2014 This endo-oriented allyl anion is stable at -78 C and undergoes diastereoselective syn-addition at the gamma-position with aldehydes and ketones to give monobenzyl-substituted 1,2-diols. Ketones 138-145 synemin Homo sapiens 84-87 19154154-7 2009 Ketones give the 4,1"-syn product while the aldehydes give the reversed selectivity to yield a 4,1"-anti product. Ketones 0-7 synemin Homo sapiens 22-25 19249831-5 2009 The linear ketones and cyclopentanone got predominant syn products whereas cyclohexanone mainly gave anti products. Ketones 11-18 synemin Homo sapiens 54-57 19691310-4 2009 Stereoselective reduction of the ketone led to either the syn- or anti-1,3-diol. Ketones 33-39 synemin Homo sapiens 58-61 18795778-4 2008 Significantly, the intramolecular hydrogen bonding in the biradicals of 8 and 9 was found to reverse their partitioning between cyclization and elimination compared with the behavior of the biradicals of ketones 3; the ketones 8-anti and 9-anti underwent cyclization in benzene, predominantly leading to cyclobutanols with syn stereochemistry between the C2 and C3 substituents. Ketones 204-211 synemin Homo sapiens 323-326 18795778-4 2008 Significantly, the intramolecular hydrogen bonding in the biradicals of 8 and 9 was found to reverse their partitioning between cyclization and elimination compared with the behavior of the biradicals of ketones 3; the ketones 8-anti and 9-anti underwent cyclization in benzene, predominantly leading to cyclobutanols with syn stereochemistry between the C2 and C3 substituents. Ketones 219-226 synemin Homo sapiens 323-326 18795778-5 2008 In accordance with photoproduct profiles, an unprecedented approximately 2-fold difference in the lifetimes of the intermediate diastereomeric triplet biradicals of ketones 8 in nonpolar solvents (e.g., tau(syn) = 123 ns and tau(anti) = 235 ns in cyclohexane) was observed via nanosecond laser flash photolysis, while no such difference in lifetimes was found for the triplet biradicals of acetoxy ketones 9. Ketones 165-172 synemin Homo sapiens 207-210 18795778-7 2008 In particular, the diastereodifferentiation in the photochemical outcomes for the diastereomers of ketone 8 and in the lifetimes of their triplet biradicals can be understood on the basis of rapid deactivation of the 8-syn triplet biradical via fragmentation and slow cyclization of the 8-anti triplet biradical from chair- and twist-boat-like hydrogen-bonded conformations, respectively. Ketones 99-105 synemin Homo sapiens 219-222 17109558-2 2006 The clicked organocatalysts were evaluated in asymmetric Michael addition of ketones to nitroolefins, showing good catalytic activity and stereoselectivity (up to 100% yield, syn:anti = 99:1, 96% ee). Ketones 77-84 synemin Homo sapiens 175-178 18163619-3 2008 For the reactions of ketones with alpha-imino esters, (R)-3-pyrrolidinecarboxylic acid was an efficient catalyst (anti/syn up to >99:1, up to 99% ee). Ketones 21-28 synemin Homo sapiens 119-122 18067310-1 2008 In a synthetic approach to the completely protected C1-C12 fragment of the macrocyclic cytotoxic agent tedanolide 1, we carried out the tin-catalyzed Mukaiyama aldol reaction between the 2,3-dialkoxypropanal 5 and the silyl enol ether 6 derived from the ketone 7, which gave, unexpectedly, the anti aldol isomer, rather than the expected syn isomer 4, as the major diastereomer formed. Ketones 254-260 synemin Homo sapiens 5-8 17914888-1 2007 Two new organocatalysts 3a and 3b, derived from L-leucine and (S)-beta-amino alcohols that were prepared from L-valine, were designed and afforded the direct syn-aldol reactions of a wide scope of aldehydes with various ketones with an excellent diastereomeric ratio of up to >20/1 and enantioselectivities of up to 99% ee. Ketones 220-227 synemin Homo sapiens 158-161 16933349-2 2006 Differences in the major reaction pathways, for example, cyclization (syn) and fragmentation (anti), adopted by the diastereomeric 1,4-radicals of ketones 2 have permitted unprecedented diastereomeric discrimination in their lifetimes to be observed by nanosecond laser flash photolysis. Ketones 147-154 synemin Homo sapiens 70-73 16939272-0 2006 Origin of syn/anti diastereoselectivity in aldehyde and ketone crotylation reactions: a combined theoretical and experimental study. Ketones 56-62 synemin Homo sapiens 10-13 16866507-5 2006 (S)-Proline or (S)-2-pyrrolidinecarboxylic acid has been reported to catalyze the Mannich-type reactions of ketones to afford the syn-products. Ketones 108-115 synemin Homo sapiens 130-133 11960455-6 2002 The first aldol process consisted of the tin triflate-mediated reaction of the aldehyde derived from 72 with enantiopure ketone 73 to generate the syn C36-C37 relationship resident in 75. Ketones 121-127 synemin Homo sapiens 147-150 16218632-1 2005 The diastereomers of ketones 2 and 3 are shown to exhibit distinct photochemical reactivities due to conformational preferences; while the anti isomers of 2 and 3 undergo efficient Yang cyclization in 75-90% yields with a remarkable diastereoselectivity (> 90%), the syn isomers predominantly undergo Norrish Type II elimination. Ketones 21-28 synemin Homo sapiens 270-273 16218632-5 2005 Additionally, it emerges from the present study that the syn and anti diastereomers of ketones 2 and 3 represent two extremes of a broad range of widely examined butyrophenones, which lead to varying degrees of Yang photocyclization depending on the alkyl substitution pattern. Ketones 87-94 synemin Homo sapiens 57-60 15563139-2 2004 Spirodiepoxides derived from allenes by oxidation are shown to give syn disubstituted ketones and their derivatives, including ortho ester, oxazoline, azido epoxide, as well as sulfonamide-, amide-, and azide-containing hydroxy ketones. Ketones 86-93 synemin Homo sapiens 68-71 15200326-2 2004 The enolate can be protonated to yield the corresponding ketone or treated with benzaldehyde to give the aldol product with good syn or anti diastereoselectivity depending on the conditions. Ketones 57-63 synemin Homo sapiens 129-132 12418896-5 2002 The other diastereomers (syn form) 4 were obtained in the reaction of tributylcinnamyltin 1a with ketones 2 by the use of BF(3) x OEt(2) instead of SnCl(2). Ketones 98-105 synemin Homo sapiens 25-28 12126428-0 2002 Stereoselective synthesis of both syn- and anti-N-tert-alkylamines using highly stereospecific crotylation of ketone-derived acylhydrazones with crotyltrichlorosilanes. Ketones 110-116 synemin Homo sapiens 16-19 11929249-0 2002 Unusual temperature dependence in the cis/trans-oxetane formation discloses competitive syn versus anti attack for the Paterno-Buchi reaction of triplet-excited ketones with cis- and trans-cylooctenes. Ketones 161-168 synemin Homo sapiens 88-91 11929249-11 2002 We propose that the cyclooctene may be competitively attacked by the triplet-excited ketone from the higher (syn) or the less (anti) substituted side; such syn and anti trajectories have hitherto not been considered. Ketones 85-91 synemin Homo sapiens 109-112 11929249-11 2002 We propose that the cyclooctene may be competitively attacked by the triplet-excited ketone from the higher (syn) or the less (anti) substituted side; such syn and anti trajectories have hitherto not been considered. Ketones 85-91 synemin Homo sapiens 156-159 11866583-5 2002 In reactions involving ketone donors where diastereoisomeric products could be formed, two adjacent stereogenic centers were created simultaneously upon carbon-carbon bond formation with complete syn-stereocontrol. Ketones 23-29 synemin Homo sapiens 196-199 11263911-3 2001 Notably, ketones with bulky silyloxy groups gave syn aldols, most likely via Z enolates. Ketones 9-16 synemin Homo sapiens 49-52 29712193-2 2001 This general method for the diastereoselective synthesis of syn, anti, and methyl ketone aldol adducts utilizes a powerful MgII -mediated, hydroxy-directed nitrile oxide cycloaddition. Ketones 82-88 synemin Homo sapiens 47-50