Ketene has been found to be a highly specific,acetylating agent for aqueous solution of proteins. It reacts only with amino, thiol, and phenolic hydroxy groups (1). Several investigators (24) have shown that the primary amino groups react most rapidly, while the hydroxy groups of tyrosine are acetylated at a much slower rate. The hydroxy groups in carbohydrate radicals of the protein molecule d...

We investigate the unimolecular dissociation of the vinoxy radical (CH2CHO) prepared with high internal energy imparted from the photodissociation of chloroacetaldehyde (CH2ClCHO) at 157 nm. Using a velocity map imaging apparatus, we measured the speed distribution of the recoiling chlorine atoms, Cl((2)P3/2) and Cl((2)P1/2), and derived from this the resulting distribution of kinetic energy, P...

2.1. Kinetic Resolution of Alcohols and Amines 2987 2.2. Ketene Acylation 2995 2.3. Cycloadditions 2996 2.3.1. â-Lactone Formation 2996 2.3.2. â-Lactam Formation 2997 2.3.3. Ketene Dimerization 2999 2.4. Halogenation 3000 2.5. Baylis−Hillman Reactions 3000 2.6. Desymmetrization of Cyclic Anhydrides 3002 2.7. C-Acylation 3004 2.8. Cyanation 3004 3. Solid Phase Chemistry 3007 3.1. Solution Cataly...

Parent cyclobutenedione 1 was photolyzed and ionized in an Ar matrix at 10K. The bisketene 2 that results in both cases (in the form of its radical cation after ionization) was characterized by its IR spectrum and by high-level quantum chemical calculations. Experiment and theory show that the neutral bisketene has only a single conformation where the two ketene moieties are nearly perpendicula...

The paper reports main results of a comprehensive study of the vibrational spectrum of ketene computed using second-order perturbation theory treatment based on quartic, cubic and semidiagonal quartic force constants. Two different models--a homogeneous model using the same density functionals and basis functions for the harmonic calculations and anharmonic corrections, and a hybrid model in wh...