ライフサイエンスコーパス: diastereomer

1 99:1 er after recrystallization of the major diastereomer).

2 membered ring system (formed as a mixture of diastereomers).

3 ing the deprotected piperidine as single cis diastereomer.

4 ne-3-carboxylates in high yields as a single diastereomer.

5 ly to the final product obtained as a single diastereomer.

6 lectivity, forming the E-alkene as the major diastereomer.

7 syn diastereomer and ca. 2 ppm for the anti diastereomer.

8 rate constant for decomposition of the minor diastereomer.

9 ng four contiguous stereocenters as a single diastereomer.

10 upported the preferential formation of the M diastereomer.

11 to provide the acyclic products as a single diastereomer.

12 configurationally lowest energy (2S,4R,4aR) diastereomer.

13 neralized anomeric effect to afford a single diastereomer.

14 yl fragment and a C6F5-unit as a single anti-diastereomer.

15 od for stereochemical assignment of a single diastereomer.

16 parative scale synthesis of a single product diastereomer.

17 ty and affords the previously unreported syn diastereomer.

18 ytic reaction is formed from the more stable diastereomer.

19 the cyclocoupling product afforded a single diastereomer.

20 ctional theory has predicted the most stable diastereomer.

21 t was found to be the cis- and not the trans-diastereomer.

22 observed for mixtures of achiral azetidinium diastereomers.

23 st cases, to oxazolines and amides as single diastereomers.

24 and highly sensitive identification of these diastereomers.

25 ison to stereoisomers such as enantiomers or diastereomers.

26 existing in solution as pairs of two racemic diastereomers.

27 high yields (up to 96%) as a mixture of two diastereomers.

28 -ketols to form [4+2] cycloadducts as single diastereomers.

29 that exists as a pair of pseudo-enantiomeric diastereomers.

30 als corresponding to pairs of conformational diastereomers.

31 stereoisomerization of the beta- and gamma- diastereomers.

32 s (HYSs), one of which produces a mixture of diastereomers.

33 f one of three hexabromocyclododecane (HBCD) diastereomers.

34 diffusion in a related set of cyclic peptide diastereomers.

35 nding hydrodimer as a mixture of meso and dl diastereomers.

36 sistent formation of predictable cyclobutane diastereomers.

37 ptane and tetrahydrofuran products as single diastereomers.

38 a[b]furan derivatives are obtained as single diastereomers.

39 rongly preferred compared to the next stable diastereomers.

40 e corresponding (2S)-2-methyl-3-ketoacyl-ACP diastereomers.

41 differences for C60 binding within the cage diastereomers.

42 vide a better basis for discriminating these diastereomers.

43 converted into either enantiomer as well as diastereomers.

44 rresponding secondary sulfonamides as single diastereomers.

45 sting of monohydroxy species and presumptive diastereomers.

46 tophanes gives rise to the two anti- and syn-diastereomers.

47 are evaluated from the syn and anti reactant diastereomers.

48 cules such as rotamers from nonequilibrating diastereomers.

49 and experimental values of NMR parameters of diastereomers.

50 oup migration to give the products as single diastereomers.

51 ontrolled discrimination process between the diastereomers.

52 syn)(/) (anti) in 85% yield and 1:1 ratio of diastereomers.

53 des B-E as well as previously unreported exo-diastereomers.

54 ross sections (CCSs) were determined for all diastereomers.

55 reactions to form trialkylboranes as single diastereomers.

56 nment of the gas-phase MW data to individual diastereomers.

57 good diastereoselectivity favoring the trans-diastereomer (11 examples with dr >/= 82:18, dr up to 92

58 on method achieve 65% yield of desired (R,S)-diastereomer 12.

59 tion of the keto function of 23, the correct diastereomer, 12-syn, was converted to lingzhiol (1) via

60 anes 16 as an approximate 1:1 mixture of two diastereomers (16A and 16B).

61 of beta-d-2'-Br,2'-F-uridine phosphoramidate diastereomers 27 and 28, as nontoxic pan-genotypic anti-

62 pharmacological characterization of the pure diastereomers (2R,7R)- and (2S,7S)-2 and a series of hom

63 cological profile, whereas the C4beta-methyl diastereomer (3) possessed dual mGlu2/3 receptor agonist

64 ynthesis of the novel unnatural parthenolide diastereomer (+/-)-4,5-dia-parthenolide was accomplished

65 further reaction of the malonate-containing diastereomer 5 with a second C60 molecule has afforded d

66 Isocyanide 5 and synthetic diastereomers 5a and 5c showed activity against Plasmodi

67 ave the corresponding dipeptides as a single diastereomer (6 examples).

68 Diastereomer 6a thermally decomposed twice as fast as 6b

69 on of a mixture of beta-aminophosphine oxide diastereomers accessed by ring-opening of an amino alcoh

70 The calculated ratio of the two diastereomers agrees with experimental observations, and

71 The synthesis of two other diastereomers allowed correction of the configuration of

72 Locked nucleic acid (LNA) and its diastereomer alpha-L-LNA are two interesting examples th

73 roton chemical shifts: ca. 7 ppm for the syn diastereomer and ca. 2 ppm for the anti diastereomer.

74 ls were proposed to predict the preferential diastereomer and its twist, and computational studies pr

75 omer is significantly more potent than the S diastereomer and N-terminal modification generally lower

76 me scales to produce two fully dechlorinated diastereomers and a tautomer, which further photodegrade

77 FR901464, spliceostatin A, six corresponding diastereomers and an evaluation of their splicing activi

78 was established by synthesizing the possible diastereomers and comparison of the data with those repo

79 ery different for the homo- and heterochiral diastereomers and of the concentration of the sample usi

80 The challenge is thereby that diastereomers and substitution isomers often give rise t

81 d with excellent yields, partially as single diastereomers and with moderate to excellent enantiosele

82 or TBBP-A, HBCDs (the alpha, beta, and gamma diastereomers), and HBCD degradation products: pentabrom

83 yl amine leading preferentially to the trans diastereomer, and free homoallylamine affording the depr

84 ctone products was determined to be the anti-diastereomer, and its formation was rationalized by a po

85 hemistry of the title compound, an unnatural diastereomer, and of a decalin building block was studie

86 stereocontrolled syntheses of trisaccharide diastereomers, and a tetrasaccharide.

87 , CMC values for the (R,R), (S,S), and (S,R) diastereomers are approximately an order of magnitude hi

88 imentally demonstrate that the trans and cis diastereomers are interconvertible under reaction condit

89 he absolute configurations of the individual diastereomers as determined from the X-ray crystallograp

90 a, 12b), and beta,gamma-CHCl (13a, 13b) dATP diastereomers as documented here, but the reductive depr

91 Generally, the reactions afford the endo-diastereomers as the major products, except for the reac

92 strictosidinic acid isomers are (R) and (S) diastereomers at their glucosylated C21 positions.

93 nters, it is generally necessary to separate diastereomers before polymerization, resulting in substa

94 stereodivergent products with anti- and syn-diastereomers both in good diastereoselectivities and en

95 sfully optimized to provide the elusive anti diastereomer by inverting a sequence of desulfinylation

96 le to "split the difference" between the two diastereomers by preparation of their corresponding unsa

97 When diastereomers can be formed, one isomer is attainable.

98 l (QM) calculations for the determination of diastereomer configurations is demonstrated using four d

99 ves access to the natural product as well as diastereomers, congeners and analogs that are currently

100 e report the synthesis of cyclic hexapeptide diastereomers containing gamma-amino acids (e.g., statin

101 The observed distribution of diastereomers corresponds to a thermodynamic ratio of is

102 Both the (5'S,4'R) and the (5'R,4'R) diastereomers could be prepared selectively in good yiel

103 yielded sodiated FLEC-AAs ions of which the diastereomers could be separated by TIMS.

104 The protein diastereomer [D-Ala(B8)]proinsulin produced higher foldi

105 r the M isomer as compared to that for the P diastereomer (DeltaDeltaG = 3.48 kcal/mol).

106 Design principles for anti diastereomer derivatives are also discussed.

107 Moreover, only a single pure diastereomer, derived from attack of the aza-anion on th

108 with previously reported results for an ShK diastereomer designated d-allo-ShK, for which significan

109 d after an efficient separation by selective diastereomer destruction.

110 eratrylglycerone) epimers, whereas the other diastereomer (differing in configuration at the beta-pos

111 ating metabolic interconversion of test HBCD diastereomers during biotransformation in trout.

112 arkably, isomers d can be converted to their diastereomers e quantitatively by heating, and e can be

113 in adducts 2-5, formation of mixtures of two diastereomers (each with their corresponding pair of ena

114 donor followed by separation of the derived diastereomers enables further advancement to either (+)-

115 trating that the mixture of the anti and syn diastereomers epimerized to the syn hydroxy ester during

116 dynamics simulations to investigate how two diastereomers (epimers) of dihydrofuroaporphine bind to

117 al peptides esculentin-1a(1-21)NH(2) and its diastereomer Esc(1-21)-1c (Esc peptides) hold promise in

118 ntimicrobial peptide (AMP) Esc(1-21) and its diastereomer Esc(1-21)-1c were found to possess potent i

119 All diastereomers exhibit a minimum surface tension of about

120 cis and trans diastereomers exhibit different reactivities, but conver

121 Diastereomers exhibited differences in their collision c

122 in their nonionic states, whereas the (R,S) diastereomer exhibits a CMC about five times larger.

123 itable acquisition and data processing, each diastereomer exhibits characteristic chemical shifts of

124 (up to 11 200 TON), while the C(2)-symmetric diastereomer favors an undesired Curtius-type rearrangem

125 Total metabolism of HBCD diastereomers followed the rank order ss > gamma > alpha

126 cyclohexane moiety rather than the tricyclic diastereomer from the (1 S,2 S)-enantiomer.

127 of these spirooxindoles, which affords four diastereomers from a single compound.

128 nzofuran derivatives were obtained as single diastereomers from cyclic or acyclic enol ethers and sty

129 of binding are nearly equal for the R and S diastereomers, greater differences are observed for the

130 We assume that one of the diastereomers has very strong optical activity, which ov

131 the starting compound, (+)-antrocin and its diastereomer have been synthesized.

132 At pH 4.0 (nonionic), all diastereomers have a critical micelle concentration (CMC

133 of organic ring systems, and the carbocyclic diastereomers have highly divergent conformational profi

134 re often observed as equilibrium mixtures of diastereomers having two different point symmetries (D2d

135 f trifluoromethyl ketone 22 gave the desired diastereomer in 32% yield and with dr = 98:2 from a 1:1

136 ion was developed which provided the desired diastereomer in 4:1 diastereoselectivity and 75% yield w

137 t alpha-HBCD would be the most dominant HBCD diastereomer in biological tissues because it was metabo

138 nce, providing selective access to the trans diastereomer in good yield.

139 e same isomer with lesser amounts of its 10R diastereomer in human epidermis.

140 dr = 99:1), which were isolated as a single diastereomer in moderate to excellent yields (41-92%).

141 lized pentacyclic intermediate 8 as a single diastereomer in one step.

142 nantioselective access to the otherwise rare diastereomer in the direct 1,4-addition of various 1,3-d

143 The selectivity for the syn diastereomer in the electrophilic activation manifolds i

144 The selectivity for the anti diastereomer in the nucleophilic manifold is explained b

145 The diaziridines are formed as a single diastereomer in up to 96% ee, containing two orthogonal

146 e continuous stereogenic centers as a single diastereomer in up to 99% ee.

147 7 + 5] fused ring system yielded inseparable diastereomers in a 1:0.6 ratio.

148 fford diverse indolizidine systems as single diastereomers in good overall yields.

149 dged stereocenter produces readily separable diastereomers in high yield (>92%) and with excellent op

150 de, and the products were obtained as single diastereomers in moderate to good yields.

151 a re-equilibration among the different cage diastereomers in order to maximize the binding affinity

152 the origin of the beta-hydroxyaspartic acid diastereomers in siderophores is reported herein.

153 ith the reported ECD assignments for the dSp diastereomers in the nucleoside context, in which the fi

154 formational preferences of the (D)P and (L)P diastereomers in the protonated peptide [YAPAA+H](+), wh

155 bsolute configuration assignments of the dSp diastereomers in which the first eluting from a Hypercar

156 ion induced slow rearrangement of the stable diastereomer into byproducts that were identified.

157 ios of chiral racemic (rac) and achiral meso diastereomers into stereosequenced crystalline polyhydro

158 rted providing a hypothesis for why a single diastereomer is observed when the chiral benzylic methyl

159 The R diastereomer is significantly more potent than the S dia

160 al chemistry, we show that the lowest energy diastereomer is the desired cis-pyran found in neopeltol

161 tions indicate that differentiation of these diastereomers is a result of the stabilization of differ

162 MR analysis, especially when the presence of diastereomers is also possible.

163 Two phosphorescent dinuclear iridium(III) diastereomers (LambdaDelta/DeltaLambda) and (LambdaLambd

164 re considerably more active than their axial diastereomers, lending strong support to crystallographi

165 riggered by metabolites M2, M13, and its two diastereomers M13-1 and M13-2.

166 marine Streptomyces sp. CNQ-617 produces two diastereomers, marineosins A and B.

167 The solvolysis of two diastereomers may give the same two products, but in dif

168 field (1)H NMR spectroscopy in which the two diastereomers (meso and +/- pair) are distinguishable.

169 ordinate complex can be isolated as a single diastereomer, methylated, and reacted with a range of nu

170 e show that the (19)F NMR spectra of 1 (~1:1 diastereomer mixture prepared by coupling of UMP-morphol

171 s was a mixture of enantiomers with no other diastereomers observed.

172 favor the formation of the cis-cyclopropane diastereomer of 1 R,2 S absolute configuration, as exper

173 Further, the 4R diastereomer of 1 was fully efficacious and approximatel

174 These findings indicate that the (R,R)-diastereomer of 1,12-Me(2)SPM represents a promising lea

175 ity, providing selective synthesis of either diastereomer of di- and trisubstituted cyclopropanes.

176 occurred and was tentatively identified as a diastereomer of I3',II8-binaringenin.

177 Additionally, the R (p) diastereomer of Me-PTEs at XT sites and both diastereome

178 rvation suggests that formation of the major diastereomer of Michael product B does not occur via an

179 LDA induces equilibration to form the minor diastereomer of Michael product B.

180 e method provides selective access to either diastereomer of optically enriched five-, six-, and seve

181 highly diastereoselective affording a single diastereomer of spirooxindoles with five consecutive asy

182 attern of the starting amide leads to either diastereomer of the alpha-methyl-alpha-ethyl-beta-hydrox

183 The reaction provides a single diastereomer of the corresponding adducts in good to hig

184 r formation, leading exclusively to a single diastereomer of the desired host.

185 The C8-diastereomer of the fully elaborated tetracyclic core of

186 lds are observed for the formation of either diastereomer of the product from a single alkene isomer.

187 ne the origin of the selectivity for the syn diastereomer of the resultant tetrasubstituted cyclobuta

188 k-flow for speciation of the enantiomers and diastereomers of 2-aminocyclohexanol as a test-bed analy

189 , two-step synthesis of a 1:1 mixture of the diastereomers of 3-bromo-2-methyl-1-propyl camphorsulfon

190 f two diastereomeric forms of 4a, and single diastereomers of 4b and 6.

191 riethylsilyl derivatives of the four racemic diastereomers of 6-(2-ethyl-1,3-dioxolan-2-yl)-5-hydroxy

192 Under dilute reduction conditions two diastereomers of a borirane-borane intermediate are isol

193 er configurations is demonstrated using four diastereomers of a trisubstituted epoxide.

194 All four diastereomers of a typical saturated oligoisoprenoid, 4,

195 We report the synthesis of both diastereomers of an all-silicon analog of decalin.

196 d photochemical deprotection, the individual diastereomers of beta,gamma-CHBr- (33a, 33b), beta,gamma

197 Conformationally locked cis diastereomers of bis(sulfide)-anchor-equipped 1,2-disila

198 translesion synthesis (TLS) across the (5'S) diastereomers of cdA and cdG.

199 One of two diastereomers of each dNTPalphaSe can be efficiently rec

200 ach is demonstrated for different use cases: diastereomers of flexible druglike molecules, E/Z-isomer

201 Diastereomers of ginsenoside-Rg3 and ginsenoside-Rh2 dem

202 The first total syntheses of two possible diastereomers of gliomasolide E, a 14-membered macrolide

203 enabled the synthesis of two of the possible diastereomers of JBIR-22 and allowed the assignment of i

204 pha-L-LNA: i.e., one of the most interesting diastereomers of LNA.

205 diastereomer of Me-PTEs at XT sites and both diastereomers of Me-PTEs at TX sites exhibited error-fre

206 ndergo Prins cyclisations to generate single diastereomers of novel tricyclic heterocycles with five

207 natural oligosaccharides (i.e., various d-/l-diastereomers of oligosaccharides as well as deoxysugars

208 k of methodology to access both syn and anti diastereomers of optically enriched, acyclic alpha,beta-

209 structure analysis of natural and unnatural diastereomers of polyhalogenated stereohexads.

210 The synthesis of both trans- and cis-diastereomers of pyrrolidinine-thioxotetrahydropyrimidin

211 est separation of DAP derivatives, including diastereomers of some of them, was achieved by MEKC in a

212 Different diastereomers of the intermediates as well as different

213 satile synthetic methodology from which four diastereomers of the most common monorhamnolipid, alpha-

214 synthesis of a library that contains all 16 diastereomers of the natural products macrosphelides A a

215 Between the two diastereomers of the PS RNA chiral center, the R(p) isom

216 The accessibility and utility of both diastereomers of these alpha,beta-disubstituted beta-ami

217 Both diastereomers of these compounds are isolated in moderat

218 describe herein the synthesis of all C13/14 diastereomers of this spiro molecule through controlled

219 ly reported the inability to distinguish the diastereomers of uridine 5'-beta,gamma-fluoromethylenetr

220 TIMS resolution (K0/DeltaK0) for the FLEC-AA diastereomers on average was 115, requiring a mobility (

221 either as a result of providing an incorrect diastereomer or due to lack of synthetic efficiency.

222 uprate reagents give either the trans or cis diastereomers or mixtures.

223 Anti-adducts were obtained as single diastereomers or with excellent diastereoselectivities w

224 Diastereomer pairs entered cells equally well, and there

225 A model "diastereomer" pathway for camptothecin biosynthesis in C

226 lenging compounds, namely amino alcohols and diastereomers possessing more than one stereocenter.

227 in the central beta-amino acid, whereas SRS diastereomers preferred an extended delta-turn (C9) conf

228 trans-1,2-disubstituted indane as the single diastereomer product.

229 pid epimerization of meso-lactide (LA) or LA diastereomers quantitatively into rac-LA.

230 etric isomers (fac/mer), and configurational diastereomers (R/S) arising from carbon stereocenters.

231 zed the first individual beta,gamma-CHX-dGTP diastereomers [(R)- or (S)-CHX, where X is F or Cl] and

232 wer epimerization occurs to provide the high diastereomer ratio observed for a majority of the produc

233 c) were determined at 195 K by measuring the diastereomer ratio of deuteration product d1-3b as a fun

234 nts were conducted: (1) determination of the diastereomer ratio of dSp products upon one-electron oxi

235 ich converged to the experimentally observed diastereomer ratios.

236 addition to the target molecule, a series of diastereomers reflective of many other isolates.

237 While the phenylene rotator in the SR diastereomer remains static even at 373 K, the RR isomer

238 -6a and (1M,5M)-9a to their (M,P)- and (P,M)-diastereomer, respectively, the possible transition stat

239 em with four examples of beta,gamma-CXY dNTP diastereomers: (S)- and (R)-beta,gamma-CHCl-dGTP (12a-1/

240 ldehydes to give the title allenes as single diastereomers (see scheme; Ts=4-toluenesulfonyl).

241 The chiral substituent allows diastereomer separation and departs during a subsequent

242 gram scale synthesis was developed utilizing diastereomer separation at a later stage in the synthesi

243 ped ion mobility-mass spectrometer for rapid diastereomer separation in the gas phase.

244 Furthermore, the diastereomer separation proved to be independent of alka

245 on of spectral features for each of the four diastereomers studied and imply structural modularity in

246 According to the calculations, the single diastereomers that are formed during the self-assembly p

247 isimide compounds, including a mixture of 21 diastereomers that cannot be deracemized at the molecula

248 H(4+) 4 Cl(-) ) as a mixture of Lambda/Delta diastereomers that separate on chiral-phase Sephadex col

249 resulted in the identification of a pair of diastereomers that showed 50-fold enzyme and cell based

250 In the pathway that generates the favored diastereomer, the oxygen lone pairs from the substituent

251 nding was that only one of the two resulting diastereomers, the SP methylphosphonate, was compatible

252 proposed structure for amphidinolide B2 and diastereomers thereof display potent antitumor activitie

253 e for the formation of an inherently favored diastereomer; this requires a high level of stereocontro

254 lution of chiral AAs was achieved by forming diastereomers through derivatization with the chiral age

255 The presence of multiple diastereomers throughout the pathway is consistent with

256 t inverse agonist (TMP778), and its inactive diastereomer (TMP776).

257 ontain clues that the preference of the (D)P diastereomer to support a trans-amide bond and the procl

258 llographically characterized as the opposite diastereomer to that expected for productive hydrogenati

259 ncoded (labelled) mixture of natural-product diastereomers to be prepared-enabled us rapidly to pinpo

260 Binding of the two (13)C-labelled glycosyl diastereomers to NKA were studied by solid-state NMR (SS

261 Through mapping characterized beta-OHAsp diastereomers to the phylogenetic tree of siderophore be

262 Yet, only one of the eight diastereomers turned out to be stable in the solvent mix

263 tification of possible conformations in each diastereomer using relaxed grid search analysis and MD s

264 anti-1",2"-syn adduct, one of eight possible diastereomers, via a diastereoselective (dr > 20) prefer

265 The unique symmetry of each diastereomer was confirmed by NMR spectroscopy.

266 In addition, the diastereomer was more efficient in reducing the systemic

267 A preference for formation of the trans diastereomer was observed in these reactions.

268 Each diastereomer was well absorbed (73-83%), and distributed

269 st-controlled access to either cis- or trans-diastereomers was achieved using 4-substituted diene sub

270 The configuration of the diaza[6]helicene diastereomers was demonstrated by time-dependent density

271 Each of the three diastereomers was isolated, and by following the equilib

272 Extensive profiling of these two phosphorous diastereomers was performed to select one for in-depth p

273 Highly sensitive detection of amino acid diastereomers was possible down to the lower nanomolar c

274 Concise syntheses of the four candidate diastereomers were achieved using a common strategy base

275 The spectroscopic properties of the C-shaped diastereomers were compared to a model compound containi

276 Three Marbon diastereomers were detected in the water and sediment sa

277 the 3R and the originally assigned 3S lysine diastereomers were independently prepared by total synth

278 The equilibria between diastereomers were influenced through variation in ligan

279 mation of the Prato monoaduct, two different diastereomers were isolated by HPLC (4, 5) whose absolut

280 values for the drug-like calibrants and two diastereomers were measured using a drift-tube instrumen

281 ple, (3S,5R,6R,9S)- and (3S,5S,6S,9S)-I(2)aa diastereomers were prepared from hexahydro-1H-azonines b

282 Guided by bioinformatics, four diastereomers were synthesized, and the relative and abs

283 The individual diastereomers were tested against HIV-1 and HIV-2 infect

284 Six key diastereomers were then synthesized to probe the importa

285 ffering metal-complexed forms adopted by the diastereomers when cationized by an alkali metal cation,

286 this study, we present the synthesis of four diastereomers which allowed the reassignment of eight st

287 synthesized and was shown to exist as three diastereomers, which interconvert via a reversible cycli

288 The two diastereomers, which show a high structural variability,

289 s eventually obtained as a 1:1 mixture of C6 diastereomers, which were readily separated by chromatog

290 structed with two chiral centers as a single diastereomer with 97% ee.

291 Each analyte enantiomer engenders a diastereomer with distinct fluorescence wavelength/inten

292 sible piperidines to provide the more stable diastereomer with high selectivity.

293 oxylic acid predominantly yielded the cyclic diastereomer with the (1 R,2 R)-2-aminocyclohexane moiet

294 nc acetate to give a mixture of two C-shaped diastereomers with cofacial bromine-substituted quinoxal

295 ramolecular cyclization to give a mixture of diastereomers with excellent diastereoselectivity (up to

296 e [4+2] cycloadducts are generated as single diastereomers with high enantiocontrol (95-98 % ee).

297 ists mainly as a mixture of cyclic hemiketal diastereomers, with an open-chain tautomer as a minor co

298 eported the (R)- and (S)-beta,gamma-CHX-dGTP diastereomers (X = F, Cl), prepared via P,C-dimorpholina

299 A single conformational isomer of the (L)P diastereomer, [YA(L)PAA+H](+), is found and assigned to

300 conversion of the enantiomeric mixture into diastereomers yielded well-resolved peaks for D and L am