- Preparation method of 2-C-methyl-4, 5-O-(1-methylvinyl)-D-arabitic acid ethyl ester
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The invention discloses a preparation method of 2-C-methyl-4, 5-O-(1-methylvinyl)-D-arabitic acid ethyl ester (formula I). Compared with the prior art, the preparation method has short reaction steps,reduces the use of organic solvents and generation of solid waste. At the same time, the used reagents are all conventional reagents, the method has the characteristics of simple operation, mild reaction conditions and environmental friendliness, and can achieve industrial preparation of 2-C-methyl-4, 5-O-(1-methylvinyl)-D-arabitic acid ethyl ester.
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Paragraph 0039-0048
(2019/01/24)
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- Spongipyran synthetic studies. Total synthesis of (+)-spongistatin 2
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Evolution of a convergent synthetic strategy to access (+)-spongistatin 2 (2), a potent cytotoxic marine macrolide, is described. Highlights of the synthesis include: development of a multicomponent dithiane-mediated linchpin union tactic, devised and implemented specifically for construction of the spongistatin AB and CD spiro ring systems; application of a CaII ion controlled acid promoted equilibration to set the thermodynamically less stable axial-equatorial stereogenicity in the CD spiroketal; use of sulfone addition/Julia methylenation sequences to unite the AB and CD fragments and introduce the C(44)-C(51) side chain; and fragment union and final elaboration to (+)-spongistatin 2 (2) exploiting Wittig olefination to unite the advanced ABCD and EF fragments, followed by regioselective Yamaguchi macrolactonization and global deprotection. Correction of the CD spiro ring stereogenicity was subsequently achieved via acid equilibration in the presence of CaII ion to furnish (+)-spongistatin 2 (2). The synthesis proceeded with a longest linear sequence of 41 steps.
- Smith III, Amos B.,Lin, Qiyan,Doughty, Victoria A.,Zhuang, Linghang,McBriar, Mark D.,Kerns, Jeffrey K.,Boldi, Armen M.,Murase, Noriaki,Moser, William H.,Brook, Christopher S.,Bennett, Clay S.,Nakayama, Kiyoshi,Sobukawa, Masao,Lee Trout, Robert E.
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supporting information; experimental part
p. 6470 - 6488
(2011/02/25)
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- CHIRAL ROUTE TO cis-CARONALDEHYDE FROM D-MANNITOL
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A chiral route to cis-caronaldehyde, a key intermediate of cis-pyrethroid insecticides as well as an efficient resolving agent for secondary alcohols, has been developed using D-mannitol as the starting material employing a sequential one-pot sodium periodate cleavage and Horner-Emmons condensation in an aqueous medium as the key stage.
- Takano, Seiichi,Kurotaki, Ayako,Takahashi, Michiyasu,Ogasawara, Kunio
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