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After alpha,alpha'-dimetalation, both 2,2'-diallyloxy-1,1'-binaphthyl and 2,2'-di-2-methylallyloxy-1,1'-binaphthyl undergo the Wittig rearrangement with perfect diastereoselectivity. When racemic 1,1'-binaphthyl-2,2'-diol ("BINOL") is used as the starting ...
Herein is reported an investigation towards the stereoselective synthesis of inherently chiral pseudorotaxanes. Chiral ammonium threads were readily prepared in five steps from racemic or enantiopure (M or P) salts of di-n-propyl-1,13-dimethoxyquinacridini ...
Sphingomonas paucimobilis B90A contains two variants, LinA1 and LinA2, of a dehydrochlorinase that catalyzes the first and second steps in the metabolism of hexachlorocyclohexanes (R. Kumari, S. Subudhi, M. Suar, G. Dhingra, V. Raina, C. Dogra, S. Lal, J. ...
A new tandem reaction leads to bicyclic cyclohexene derivatives with complete control of the relative configuration of the four chiral centers formed. The high diastereoselectivity is the consequence of an endo-selective Diels-Alder reaction followed by an ...
A concise, practical and stereoselective total synthesis of galantinic acid, constituent of the peptide antibiotic galantin, is reported. The title compound is obtained in six steps via Heathcock-Claisen condensation, Evans reduction and deprotection in 10 ...
Efficient methods for the stereoselective synthesis of polyfunctional (E)- and (2)-alkenes and conjugated (EE)- and (E,2)-dienones are presented. They rely upon one-pot, four-component processes that condense 1-oxy-1,3-dienes, silyl enol ethers, SO2, and c ...
New conditions have been found for the desulfitative Mizoroki-Heck arylation and trifluoromethylation of mono- and disubustituted olefins with arenesulfonyl and trifluoromethanesulfonyl chlorides. Thus (E)1,2-disubstituted alkenes with high stereoselectivi ...
A new sulfur dioxide-based organic chemistry has been developed as a novel approach for the stereoselective synthesis of polyene fragments based on our one-pot, four-component synthesis of polyfunctional alpha-alkanesulfonyl-gamma,delta-unsaturated ketones ...
The reaction of aldehydes and ketones, including aliph. and arom. ones, with amides of alpha -isocyano-beta -phenylpropionic acid in toluene in the presence of lithium bromide gives 2,4,5-trisubstituted oxazoles in good to excellent yield. Protected chiral ...
N-Benzyloxycarbonyl-2,5-dideoxy-2,5-imino-3,4-O-isopropylidene-L-ribose 12a has been converted into (1R,2S,6R, 7S,7aS)-5 and (1R, 2S, 6S, 7R, 7aR)-1,2,6,7-tetrahydroxypyrrolidin-5-ones 6 and (1R,2S,6S,7S,7aS)-7 and (1R,2S,6R,7R,7aS)-1,2,6,7-tetrahydroxypyr ...
