共查询到20条相似文献,搜索用时 15 毫秒
1.
Ke Wang Zuyi Li Chengye Yuan 《Phosphorus, sulfur, and silicon and the related elements》2013,188(6-7):1797-1800
Bioreduction of 2-oxo-3-halo (or azido) alkanephosphonates and 4-ethoxy-4,2-dioxobutanephosphonates by baker's yeast afforded 3-substituted 2-hydroxyalkanephosphonates in moderate to good yields and ee value. Moreover, a regio- and stereoselective bioreduction of 2,3-dioxoalkanephosphonates and 2,4-dioxoalkanephosphonates by baker's yeast was studied also. The resulting chiral hydroxy compounds can be used as chirons for the stereoselective synthesis of biologically active molecules. 相似文献
2.
A highly concise and stereoselective total synthesis of (5R,7S)‐kurzilactone ( 1 ) was performed by a convergent approach by means of a Jacobsen's hydrolytic kinetic resolution, a Horner? Wadsworth? Emmons reaction for the construction of the α,β‐unsaturated δ‐lactone ring system, and a highly diastereoselective Mukaiyama aldol reaction for the introduction of the formal anti‐1,3‐diol unit (Schemes 2 and 3). 相似文献
3.
A practical stereoselective synthesis of (S)‐bakuchiol ( 1 ) and its enantiomer is reported. The important intermediate, (R)‐configured β‐siloxy aldehyde 5 , was obtained in three steps from the easily available material geraniol ( 2 ) via the key step of Yamamoto's rearrangement of epoxy silyl ethers. (S)‐Bakuchiol ( 1 ) and its enantiomer, (R)‐bakuchiol ( 17 ), were finally obtained in different synthetic sequences with overall yields of 51% (ten steps) and 40% (nine steps) from geraniol ( 2 ), respectively. 相似文献
4.
Baggu Chinnababu Sudina Purushotham Reddy Chitturi Bhujanga Rao Karuturi Rajesh Yenamandra Venkateswarlu 《Helvetica chimica acta》2010,93(10):1960-1966
A simple and highly efficient stereoselective total synthesis of dodoneine ( 1 ), a naturally occurring bioactive 5,6‐dihydro‐2H‐pyran‐2‐one, was achieved. The synthesis involved Keck's asymmetric allylation, iodine‐induced electrophilic cyclization, and Grubbs' catalyzed ring‐closing metathesis as key steps. 相似文献
5.
LI Wei HUANG Hai JIN Xiaodong LIU Yujian XU Chaohang ZHU Hongjun 《高等学校化学研究》2014,30(5):770-773
The authors described a short and highly enantioselective route to (R)-salmeterol involving asymmetric synthesis of cyanohydrin followed by nucleophilic substitution with 6-(4-phenylbutoxy) hexyl methanesulfonate. 相似文献
6.
A stereoselective synthesis of (3R, 4S)-N-BOC-Statine was achieved through an aldol condensation of N-BOC-L-Leucinal with a boron enolate of an appropriate chiral auxiliary described by Evans. 相似文献
7.
Sudina Purushotham Reddy Baggu Chinnababu Yenamandra Venkateswarlu 《Helvetica chimica acta》2014,97(7):999-1003
The first concise stereoselective total synthesis of diarylheptanoid rhoiptelol C ( 1 ) was achieved from readily available vanillin. The synthesis involves Keck's asymmetric allylation, olefin cross metathesis, and Sharpless asymmetric dihydroxylation reaction as key steps. 相似文献
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Baggu Chinnababu Sudina Purushotham Reddy Kunuru Venkatesham Dasireddi Chandra Rao Yenamandra Venkateswarlu 《Helvetica chimica acta》2014,97(5):613-618
A simple and highly efficient synthetic route has been developed for synthesis of 1‐(4‐hydroxyphenyl)nonadecane‐3,5‐diol ( 1 ). The two stereogenic centers were generated by employing proline asymmetric α‐hydroxylation (MacMillan α‐hydroxylation), Jacobsen's hydrolytic kinetic resolution (HKR), and, finally, Yamaguchi oxirane opening as key steps (Scheme 2). 相似文献
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The natural furocoumarin dehydroxyglaupalol and two analogs were prepared by reaction of the appropriate 4-hydroxy-coumarin with 3-chloro-3-methylbutyne in basic medium, followed by catalytic hydrogenation of the exo double bond. 相似文献
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13.
Pannala Padmaja Pedavenkatagari Narayana Reddy Jhillu Singh Yadav 《Helvetica chimica acta》2016,99(7):506-512
The stereoselective synthesis of key fragments 3 and 7 of elaiophylin has been accomplished from readily available epichlorohydrin as the starting material. The key reactions involved are Jacobsen's kinetic resolution, Prins cyclization, pyridinium chlorochromate‐mediated oxidative cleavage, Grignard reaction, and cross‐metathesis reaction. 相似文献
14.
Karuturi Rajesh Vangaru Suresh Jondoss Jon Paul Selvam Chitturi Bhujanga Rao Yenamandra Venkateswarlu 《Helvetica chimica acta》2009,92(9):1866-1872
A simple and highly efficient stereoselective total synthesis of xestodecalactone C ( IIb ), a polyketide natural product, was achieved (Scheme 2). The synthesis involved Keck's asymmetric allylation, a iodine‐induced electrophilic cyclization, and an intramolecular Friedel–Crafts acylation as key steps. 相似文献
15.
A simple and highly efficient synthetic route has been developed for analogue of HMGCo A reductase inhibitor (1). The strategy utilizes S-Corey–Bakshi–Shibata (CBS) reduction, FeCl3-catalyzed C-H insertion of ethyl diazoacetate. [Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource: Full experimental and spectral details.] 相似文献
16.
Lígia M. Rodrigues Carla S. Francisco Ana M. F. Oliveira-Campos Abdellatif M. Salaheldin 《合成通讯》2013,43(24):4369-4378
Synthesis of 11 tacrine analogs derived from N-aryl-5-amino-4-cyanopyrazoles, by a Friedländer type reaction, is described. Their structures were confirmed by 1H and 13C NMR spectroscopy, elemental analysis, and/or mass spectrometry. 相似文献
17.
Xiao Zhen JIAO Ping XIE* Lian Suo ZU Xiao Tian LIANG Institute of Materia Medica Chinese Academy of Medical Sciences & Peking Union Medical College Beijing 《中国化学快报》2003,14(2)
The lactone neocnidilide 8 occur in the roots of Cnidilide officinale1 which is shown to inhibit the growth and toxin production of mycotoxin-producing fungi2. Although The synthesis of lactones 7, which is stereoisomer of cnidilide, and 8 had been reported by others3, 4, we would like to report the highly stereoselective synthesis of its racemic isomer 8 as shown in Scheme 1. Scheme 1 COOHHOOCbcOOHH1234d5eOHOHHH 6fOOHHH 7g8COOHOHa12345673a7aOHHOH1235673 a7a1234561'1'2'… 相似文献
18.
First Stereoselective Synthesis of the Cytotoxic Polyketide (4R)‐1‐(3,5‐Dihydroxyphenyl)‐4‐hydroxypentan‐2‐one 下载免费PDF全文
Kothakonda Rajendra Prasad Sudina Purushotham Reddy Katragadda Suresh Babu Janaswamy Madhusudana Rao 《Helvetica chimica acta》2015,98(1):143-147
The first stereoselective synthesis of the cytotoxic polyketide (4R)‐1‐(3,5‐dihydroxyphenyl)‐4‐hydroxypentan‐2‐one ( 1 ) was achieved from readily available propylene oxide and 3,5‐dimethoxybenzyl alcohol. The synthesis involves Jacobsen's hydrolytic kinetic resolution (HKR) and Grignard reaction as key steps. 相似文献
19.
G. Veeresa 《合成通讯》2013,43(8):1479-1487
An efficient method has been developed for the stereoselective synthesis of N-Boc-AHPPA (7), a biologically important amino acid of non-proteinogenic origin. 相似文献
20.
The catalytic effect of baker's yeast on the hydrolysis of aliphatic esters in p-acetoxybenzoates is described. The chemoselective character of this reaction enables the selective protection of the hydroxyl group in p-hydroxybenzoic acid derivatives. 相似文献