An efficient partial 5-step synthesis of 4'-O-methylquercetin from quercetin in 63% yield is reported. This strategy relies on the selective protection of the catechol group with dichlorodiphenylmethane in diphenyl ether as solvent and on the selective protection of the hydroxyl groups at positions 3 and 7 with chloromethyl ether.

The title compound, C(21)H(25)NO(2)S, consists of a five-membered heterocyclic ring, with pendant phenyl groups, an isopropyl group and a thio-ether residue. The thio-ether bonds to the heterocycle via the N atom. The absolute configuration results from an inversion of the configuration of substrate during the synthesis.

3.1 PRODUCTION OF CLEAN SYNTHESIS GAS......................................................................... 9 3.1.1 Biomass Gasification .............................................................................................. 9 3.1.2 Gas Cleanup.......................................................................................................... 10 3.2 CONVERSION OF SYNTHESIS GAS T...

The first total synthesis of the proposed structure of cytotoxic macrolide maltepolide C has been achieved via an E-selective intramolecular Heck cyclization as a key step. Other key features of the synthesis are Z-selective Wittig olefination, Sharpless asymmetric dihydroxylation followed by Williamson-type cyclo-etherification, Brown asymmetric allylation, and Noyori reduction of an alkynone....

This article contains original experimental data, figures and methods to the preparation of non-isocyanate poly(hydroxyurethanes) by an environmentally friendly method without the use of toxic phosgene and isocyanates from bis(2,3-dihydroxypropyl)ether dicarbonate and various diamines (Tryznowski et al., Submitted for publication) [1]. Bis(2,3-dihydroxypropyl)ether dicarbonate was obtained from...

0002-7863/82/1504-6842$01.25/0 the original alcohol substituent. Similar annulations from allylic alcohols via unsymmetrical diallyl ethers are demonstrated by Table I1 entries g-j. The requisite diallyl ethers for photoannulation of 2g-j are readily available by Williamson synthesis from the hydroxy olefin precursors indicated. It is noteworthy that the stereochemistry of the substituent R' in...

The protection of functional group is unavoidable in multi-step organic synthesis. Along with tetrahydropyranyl (THP) ethers, t-butyldimethylsilyl (TBDMS) ethers have been widely used for protecting hydroxyl groups. TBDMS ether is more stable to hydrolysis than trimethylsilyl ether, but is still readily cleaved by a variety of selective conditions. The deprotection of TBDMS is usually under mil...