Phosphonate–Phosphinate Rearrangement

Genome Rearrangement

The difference between genome rearrangement theory and other approaches to comparative genomics, and indeed most other topics in computational molecular biology, is that it is not directly based on macromolecular sequences, either nucleic acids or proteins. Rather like classical genetics, its building blocks are genes, and the structures of interest are chromosomes, abstracted in terms of the l...

Immunoglobulin λ Gene Rearrangement Can Precede κ Gene Rearrangement

Immunoglobulin genes are generated during differentiation of B lymphocytes by joining gene segments. A mouse pre-B cell contains a functional immunoglobulin heavy-chain gene, but no light-chain gene. Although there is only one heavy-chain locus, there are two light-chain loci: kappa and lambda. It has been reported that kappa loci in the germ-line configuration are never (in man) or very rarely...

Aza-pinacol rearrangement: acid-catalyzed rearrangement of aziridines to imines.

A series of di-, tri-, and tetra-substituted N-tosylaziridines [N-(toluene-p-sulfonyl)aziridines] 1, prepared by aziridination of the corresponding alkenes with N-[(tolyl-p-sulfonyl)imino]phenyliodinane (TsN = IPh), was found to undergo a BF3-catalyzed rearrangement (aza-pinacol rearrangement) under mild conditions to give the corresponding N-tosylimines 2 generally in satisfactory yields.

The Claisen Rearrangement

Antarafacial-Antarafacial Cope Rearrangement

Thermal rearrangement of 2-thiabicyclo[ 3.2.0]hepta-3,6-diene-6,7-dicarbonitriles 1-3 to their 4,5-dicarbonitrile isomers 4-6 takes place at 110-140 "C in yields of 82-84%. The reactions are first order with rates almost independent of the polarity of the solvent. Activation parameters (m = 120-140 kJ mol-' and AS* = 0 J K-l mol-') are in agreement with a concerted symmetry-allowed antarafacial...