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本文以樟脑衍生物(-)-莰烷磺内酰胺(2)为原料,经N-烷酰基莰烷-2,10-磺内酚胺(3)与碘代烷的不对称烷基化反应,用二锂代乙基苯基砜取代磺内酰胺助剂以及铝汞还原性脱硫反应等三步合成(S)和(R)一切叶蚁警戒信息素(1),其光学纯度高达95%e.e以上。 相似文献
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Subsequent treatment of N-crotoyl-(1S,2R)-bornane-10,2-sultam with EtMgCl, recrystallization of the product and saponification, afforded R-(-)-3-methylpenthanoic acid which was used for acylation of (1R,2S)-bornane-10,2-sultam. The product was converted into N-[(2S,3R)-2-amino-3-methylpentanoyl]-(1R,2S)-bornane-10,2-sultam by hydroxyamination with 1-chloro-1-nitrosocyclohexane, followed by reduction of the hydroxylamine grouping. Saponification of the sultam imide provided (+)-alloisoleucine. 相似文献
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Zbigniew Czarnocki Jzef B. Mieczkowski Jaroslaw Kiegiel Zbigniew Ara
ny 《Tetrahedron: Asymmetry》1995,6(12):2899-2902
(2R)-N-Glyoxyloylbornane-10,2-sultam reacted with dopamine hydrochloride, forming the Pictet-Spengler condensation product, which was further converted into (S)-(+)-N)-methylcalycotomine of high enantiomeric purity. The same kind of reaction with tryptamine hydrochloride gave the condensation product with 100% d.e. 相似文献
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Jaroslaw Kiegiel Christian Chapuis Zofia Urbaczyk-Lipkowska Janusz Jurczak 《Helvetica chimica acta》1998,81(9):1672-1680
Cycloadditions of 1-methoxybuta-1,3-diene to (2R)-N-pyruvoyl and (2R)-N-(phenylglyoxyloyl)bornane-10,2-sultam ((−)- 1b and (−)- 1c , resp.) under high-pressure conditions are presented. The absolute configurations of the cycloadducts 2b,c and of their resulting reduced alcohols 3b,c are based on their X-ray analyses. The stereochemical course of these reactions is discussed and compared to the inverse diastereoselectivity observed for the analogous cycloaddition to (2R)-N-glyoxyloylbornane-10,2-sultam ( 1a ) 相似文献
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Asymmetric silyl nitronate cycloadditions with N-acryloyl (2R)-bornane-10,2-sultam, N-acryloyl (2S)-bornane-10,2-sultam, and N-methacryloyl (2R)-bornane-10,2-sultam have been studied. The asymmetric silyl nitronate cycloaddidon/elimination methodology provides a general route for the asymmetric synthesis of 2-isoxazolines. 相似文献
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Tomasz Bauer Christian Chapuis Jaroslaw Kiegiel Janusz W. Krajewski Katarzyna Piechota Zofia Urbanczyk-Lipkowska Janusz Jurczak 《Helvetica chimica acta》1996,79(4):1059-1066
An efficient synthesis of the two title compounds is reported, as well as their X-ray crystal-structure analyses. A discussion based on stereoelectronic considerations rationalizes the first example of a crystalline SO2/C(O) syn-periplanar conformer of a N-acylbornane-10,2-sultam. 相似文献
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《Tetrahedron: Asymmetry》2000,11(22):4581-4591
A correlation between the solvent polarity and the logarithm of the diastereoisomer ratio (dr) was found for the uncatalyzed [4+2] cycloaddition of cyclopentadiene to N,N′-fumaroyldi[(2R)-bornane-10,2-(2′-phenyl-pyrazol-3′-one)]. Using the Abboud–Abraham–Kamlet–Taft parameters, predictive values for this method resulted in an optimum diastereoisomeric excess (de) of more than 97% in hexane. Implications for the stereochemical course of the reaction as well as a comparison with the analogous (2R)-bornane-10,2-sultam auxiliary are discussed. 相似文献
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《Tetrahedron: Asymmetry》1999,10(3):535-541
N-Methylglyoxyloyl- (1a) and N-phenylglyoxyloyl-(2R)-bornane-10,2-sultam (1b), when reduced under various conditions, afford mixtures of two diastereoisomeric alcohols. In both cases, the reaction conditions lead to excess of both (S) and (R) configuration at the newly created stereogenic center of diastereomeric products have been found. 相似文献
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Katarzyna Kiegiel Tomasz Baakier Piotr Kwiatkowski Janusz Jurczak 《Tetrahedron: Asymmetry》2004,15(24):3869-3878
The diastereoselective addition of allylsilanes and allylstannanes to N-glyoxyloyl-(2R)-bornane-10,2-sultam 1 and (1R)-8-phenylmenthyl glyoxylate 7 in the presence of Lewis acids has been studied. We obtained diastereoselectivities up to 84% and 94% for the allylation of 2 and 7, respectively. The application of the allylation products of 1 or 2 in the synthesis of 4-butanolides, for example (2S,4S)-2-hydroxy-4-hydroxymethyl-4-butanolide 13 is presented. 相似文献
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Wolfgang Oppolzer Christophe Darcel Patrick Rochet Stephane Rosset Jef De Brabander 《Helvetica chimica acta》1997,80(5):1319-1337
α-Substituted N-acylbornane-10, 2 -sultams 6, 9 , and 10 can be converted into enantiomerically pure ketones 5. 13 , and 14 , respectively, via a two-step procedure involving a known mercaptolysis reaction followed by an [Fe(acac)3]-mediated coupling of the resulting S-benzyl thioesters with Grignard reagents. Furthermore, enantiomerically pure aldehydes 23 can be obtained from α-substituted N-acylbornane-10,2-sultams 6 via a one-step reduction with (i-Bu)2AIH. No epimerization at the α-chiral center is observed during the cleavage reaction whereby the chiral auxiliary, bornane-10,2-sultam 1 or ent- l , was recovered. By using this methodology, several natural products or precursors thereof can be prepared. 相似文献
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N-Glyoxyloyl-(2R)-bornane-10,2-sultam and (1R)-8-phenylmenthyl glyoxylate react stereoselectively with simple nitro compounds giving diastereoisomeric nitroalcohols with high asymmetric induction. N-Glyoxyloyl-(2R)-bornane-10,2-sultam 1a is shown to be a highly efficient chiral inducer, superior to (1R)-8-phenylmenthyl glyoxylate 1b. In all cases, the absolute (2S) configuration at the center bearing the hydroxy group and the relative syn configuration for the major diastereoisomers were determined. 相似文献