排序方式: 共有11条查询结果,搜索用时 15 毫秒
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Benan K?lba?Author VitaeMetin BalciAuthor Vitae 《Tetrahedron》2011,67(13):2355-2389
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Avinash K. Srivastava Munsaf Ali Kamal Nayan Sharma Raj K. Joshi 《Tetrahedron letters》2018,59(33):3188-3193
A toluene solution of β-chlorocinnamaldehyde and dihydroxy alcohols in the catalytic presence of para-toluenesulphonic acid (PTSA) yield the β-ketoacetal in good to outstanding amount. The catalyst (PTSA), first selectively protect the aldehydic group to form the β-chloroacetal and the subsequent dechlorination by H2O result the β-ketoacetal. Significant transformation was achieved with electron donating substituent attached at the para-position of cinnamaldehyde. The selective formation of β-keto-1,3-acetal was also obtained with a mixture of 1, 2- and 1, 3- diol. The present reaction consists of a metal-free, economical, robustly feasible, sizeable functional group tolerance and high yield properties. Moreover, the use of different dihydroxy alcohols made this process more benign and valuable towards the metal-free development of ketones. First, of its kind, a rare and unusual multitasking nature of PTSA is observed. 相似文献
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A metal-free procedure for the regioselective hydration of internal arylalkynes under microwave irradiation is described. The reaction promoted by PTSA takes place rapidly in EtOH and regioselectively afforded in good yields various carbonyl compounds 2. 相似文献
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Nandkishor N. Karade Girdharilal B. Tiwari Sandeep V. Shinde Sumeet V. Gampawar Jeevan M. Kondre 《Tetrahedron letters》2008,49(21):3441-3443
The solvent-free synthesis of 1-(p-toluenesulfonyloxy)-1,2-benziodoxol-3(1H)-one is reported from Dess-Martin periodinane and p-toluenesulfonic acid monohydrate using a grinding technique and is subsequently utilized for the α-tosyloxylation of a range of enolisable ketones. 相似文献
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Stereoselective total synthesis of obolactone by the Brønsted acid (PTSA) mediated tandem cyclization of the appropriately substituted diketone in one-pot in a highly selective and efficient manner is reported. 相似文献
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A concise and convergent synthesis of the C-glycoside analogue 2b of immunomodulating α-galactosylceramide OCH 1b starting from readily available 2,3,4,6-tetra-O-benzyl-d-galactose 3 and l-arabinose 6 is described. The synthesis features the nucleophilic addition of an α-ethynyl sugar 5 to the phytosphingosine-precursor aldehyde 9 and would be applicable to a variety of C-glycoside analogues of interest. 相似文献