Optimal Coherent Filtering for Single Noisy Photons.

We introduce a filter using a noise-free quantum buffer with large optical bandwidth that can both filter temporal-spectral modes as well as interconvert them and change their frequency. We theoretically show that such quantum buffers optimally filter out temporal-spectral noise, producing identical single photons from many distinguishable noisy single-photon sources with the minimum required reduction in brightness. We then experimentally demonstrate a noise-free quantum buffer in a warm atomic system that is well matched to quantum dots. Based on these experiments, simulations show that our buffer can outperform all intensity (incoherent) filtering schemes for increasing indistinguishability.

Synthesis of the cyclohexan subunit of baconipyrones A and B from furan.

[figure: see text] The synthesis of the cyclohexan subunit of the siphonarlid metabolites baconipyrones A and B from furan is described. A key step included the alkylative ring opening of 7-oxanorbornenic sulfone 4 and oxidative desulfonylation of compound 8.

Building a small polypropionate library. Synthesis of all possible stereotetrads (building blocks for polyketide synthesis) from furan.

The all diastereomeric stereotetrads (polypropionate fragments) were synthesized in a stereodivergent fashion, starting from the Diels-Alder adducts of furan with acrylic acid and (-)-2-camphanoxyacrylonitrile, respectively. The key intermediates of these sequences were the oxanorbornenic sulfones 7, (-)-53 and (+)-54. Regio- and stereocontrolled alkylative ring opening of these intermediates afforded the cyclohexenyl sulfones 14, (+)-55 and (-)-58 which were transformed into the desired stereotetrads 30, 31, 40, 41, (+)-62, (+)-63, (-)-66, and (+)-69.

Total synthesis of (+)-7-deoxypancratistatin from furan.

A new total synthesis of (+)-7-deoxypancratistatin 1 has been accomplished in 19 steps (8% overall yield) from two readly available compounds, furan and trans-1,2-bis(phenylsulfonyl)ethylene.