Aminoborohydrides. 13. Facile reduction of N-alkyl lactams with 9-borabicyclo[3.3.1]nonane (9-BBN) and lithium aminoborohydrides (LAB) reagents

Aminoborohydrides. 13. facile reduction of N-alkyl lactams with 9- borabicyclo[3.3.1]nonane (9-BBN) and lithium aminoborohydrides (LAB) reagents

Two methods to reduce N-alkyl lactams to the corresponding cyclic amines using 9borabicyclo[3.3.1]nonane (9-BBN) and lithium aminoborohydride (LAB) reagents are reported. The lactam reductions required 2.2 molar equivalents of 9-BBN or 1.5 molar equivalents of LAB reagent and were complete within two hours in refluxing THF (65 °C). Reductions with these reagents are chemoselective and complemen...

TREC-9 Cross-lingual Retrieval at BBN

9. Quantum chromodynamics 13

QCD To reduce the size of this section's PostScript file, we have divided it into two PostScript files. We present the following index: PART 1 Page # Section name 1 9.1 The QCD Lagrangian 2 9.2 The QCD coupling and renormalization scheme 6 9.3 QCD in deep-inelastic scattering 9 9.4 QCD in decays of the τ lepton 11 9.5 QCD in high-energy hadron collisions PART 2

THE ROLE OF CHLOROMETHYL ETHERS IN THE FORMATION OF N(7) - AND N(9)-ALKYLATED ISOMERS OF ADENINE SYNTHESIS OF 2-[9-(ETHOXYMETHYL) ADENYL] PHOSPHONATE

The structural features of chloromethyl ethers are shown to have a significant effect on the formation of N(7)- or N(9)- alkylated isomers of purine acyclo-nucleosides. The chemical synthesis of 2-[9-(ethoxymethyl) adenyl] phosphonate is described. This compound is active against herpesviruses.

Week 9: Dimensionality Reduction

In the preceding lectures, we discussed clustering. One view of clustering is that it’s a way to summarize a complex real-valued datapoint x ∈ R with a single categorical variable y ∈ {1, . . . ,K}. This could be useful for understanding and visualizing the structure in the data, as well as a preprocessing step for other learning algorithms. For example, we could build a very simple classifier ...