Enynes undergo stereoselective syn intramolecular bromoetherification; the stereochemical course of the reaction was elucidated by X-ray crystallographic studies and by stereospecific synthesis of authentic bromoallenes.

A spiro[5.5]ketal library embodying the core structure of numerous biologically active natural products was synthesized employing a double intramolecular hetero Michael reaction as a key transformation.

An efficient synthesis of tetrasubstituted furans was achieved from the corresponding α,β-unsaturated ketone derivatives, acid chlorides, and Bu3P in the presence of Et3N via a chemoselective intramolecular Wittig reaction as the key step. The presence of an additional electron-withdrawing group in the α-position of Michael acceptors controlled the chemoselectivities of presumable phosphorus yl...

The reactivity of 3-substituted 4-methyl-4-(3-oxobutyl)-2-cyclohexen-1-ones (1) in the presence of a combination of a Lewis acid and a 1,2-diol was studied. The results suggest several factors that influence 6-membered ring formation, including two types of intramolecular aldol reaction and intramolecular 1,4-addition, due to the C3-substituent, Lewis acid, and the presence of diol. In this stu...

The development of new catalytic asymmetric reactions continues to be a major goal in organic chemistry. Here we report a novel antibody-catalyzed intramolecular Michael addition of aldehydes and ketones to enones. The reaction is enantioselective and diastereoselective with a high ee value and cis/trans ratio. This is the first example of asymmetric intramolecular Michael addition of ketones. ...

Diphtheria toxoid, the principle component of diphtheria vaccines, is prepared by inactivating diphtheria toxin with formaldehyde and glycine. The treatment introduces intramolecular cross-links and intermolecular formaldehyde/glycine adducts in diphtheria toxin. The purpose of the present study was to elucidate the nature and location of formaldehyde-induced modifications at two functional sit...

Intramolecular cycloadditions between cyclobutadiene and olefins can provide highly functionalized cyclobutene-containing products. The outcome of the reaction depends on the nature of the tether connecting the two reactive partners in the cycloaddition. Electronically unactivated olefins attached to cyclobutadiene through a three-atom, heteroatom-containing tether yield successfully the desire...

In this work we analyze the whole molecular mechanism for intramolecular aromatic hydroxylation through O2 activation by a Schiff hexaazamacrocyclic dicopper(I) complex, [Cu(I) 2(bsH2m)](2+). Assisted by DFT calculations, we unravel the reaction pathway for the overall intramolecular aromatic hydroxylation, i.e., from the initial O2 reaction with the dicopper(I) species to first form a Cu(I)Cu(...

Understanding intramolecular energy flow in molecules is one of the central goals of chemical physics. Statistical theories [such as Rice-Ramsperger-Kassel-MarCus (RRKM) theory] of unimolecular reaction rates, which assume that the vibrational degrees of freedom rapidly exchange energy, have proved extremely successful (1). Recent work on small molecules has provided rigorous tests of these the...

The formal intramolecular photoredox reaction initially discovered for the parent 2-(hydroxymethyl)anthraquinone (1) has been extended to include analogs 3-6 in which the oxidizable benzyl alcohol group is significantly further away from the anthraquinone moiety. All of 3-6 undergo a clean and efficient formal intramolecular photoredox reaction in water catalyzed by acid (Phi = 0.1-0.6), in whi...