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41.
Syntheses of bioactive monoterpenoids pleurolactone, dihydro-3-epi-pleurolactone, 6,7-dihydroxymintlactone and their furanoid sesquiterpene analogs have been accomplished. 相似文献
42.
The enantioselective total synthesis of cineromycin B, a 14-membered unsaturated macrolide with two doubly allylic alcohols, was completed using a Julia coupling, an oxidative [2,3]-sigmatropic rearrangement of selenide, and a Yamaguchi macrolactonization as key reactions. 相似文献
43.
A concise and efficient synthesis of α,α′,β-trisubstituted β-lactones is presented. These novel lactones are easily obtained in five steps and will be dedicated to anionic ring opening polymerization. 相似文献
44.
The concept of lactonization-mediated and related glycosylations led us to develop new methods of glycosylation such as the 2'-carboxybenzyl (CB) glycoside method, the glycosyl pentenoate/phenylselenyl trifluoromethanesulfonate (PhSeOTf) method, and the glycosyl aryl phthalate method. Highly stereoselective beta-mannopyranosylations were achieved by employing the CB glycoside and the glycosyl pentenoate/PhSeOTf methods. The CB glycoside method was also utilized for stereoselective 2-deoxyglycosylation, beta-arabinofuranosylation, and alpha-galactofuranosylation. In addition, these lactonization-mediated methods of glycosylation were employed for the synthesis of complex oligosaccharides. In particular, the CB glycoside method was successfully applied to the synthesis of repeating oligosaccharide subunits of the O-polysaccharide of the lipopolysaccharide from Danish Helicobacter pylori strains and Escherichia coli 077, the synthesis of oligoarabinofuranosides in mycobacterial cell walls, and the total synthesis of antineoplastic agelagalastatin. 相似文献
45.
46.
Ravindar Kotla Radhakrishnamraju Ruddarraju P. Aparna Shobha Donthabakthuni Gattu Sridhar 《合成通讯》2018,48(7):747-752
The total synthesis of 14-membered resorcylic acid macrolide, β-zearalenol, was accomplished starting from commercially available enantiomerically pure propylene oxide and methyl 2,4-dihydroxy-6-methylbenzoate using Grignard reaction, asymmetric dihydroxylation, Yamaguchi macrolactonization, and ring-closing metathesis as key steps. 相似文献
47.
Bandi Chennakesava Reddy Vikas Madhukar Bangade Palakuri Ramesh Harshadas Mitaram Meshram 《Helvetica chimica acta》2013,96(2):266-274
A stereoselective total synthesis of multiplolide A ( 1 ) and of its diastereoisomer 2 was described from easily accessible starting materials (Schemes 2–4). The synthetic strategy involves a Jacobsen resolution, Sharpless epoxidation, Swern oxidation, Yamaguchi reaction, and ring‐closing metathesis (RCM). 相似文献
48.
Iodine monochloride (ICl) was discovered to be a highly efficient, green oxidant, which can oxidize aldose hemiacetals, diarylmethanols, arylalkylmethanols, anddialkylmethanols to the corresponding aldose lactones, diarylmethanones, arylalkylmethanones, and dialkylmethanones, respectively, in high yields. ICl as a green, metal-free oxidant is characterized by mild reaction condition, short reaction time, good yield, and broad scope. 相似文献
49.
Debendra K. Mohapatra Gokarneswar Sahoo Dhondi K. Ramesh J. Srinivasa Rao G. Narahari Sastry 《Tetrahedron letters》2009,50(40):5636-5639
The total syntheses of decarestrictines C1 and C2 have been described. The synthetic strategy involves a practical and flexible approach using esterification and ring-closing metathesis to unite the acid and alcohol fragments. The acid fragments are enantiomers of each other and have been prepared from l-(−)-malic acid via similar transformations; in Sharpless asymmetric epoxidation, (+)-DET has been used for decarestrictine C1 and (−)-DET for decarestrictine C2. The alcohol fragment is identical for both decarestrictines C1 and C2 and has been accessed from d-(+)-mannitol. Comparison of the 1H and 13C NMR data combined with the computational studies predicts the presence of two conformations without and with hydrogen bonding (conformational isomers I and II for decarestrictine C1), respectively. The 1H and 13C NMR data for decarestrictine C2 completely agreed with the analytical data reported by Kibayashi et al. 相似文献
50.
The asymmetric synthesis of (+)-Cladospolide C has been achieved in 11 steps with 26% overall yield. Key steps in the sequence involve KAPA-promoted alkyne Zipper reaction, TPP-promoted enyne ester (ynoate) to diene ester (dienoate) isomerization, Sharpless asymmetric dihydroxylation and Yamaguchi macrolactonization. 相似文献