A convergent synthesis of octadeca-2E, 13Z-dienyl acetate, a pheromone component ofSynanthedon tipuliformis C.

A convergent synthesis of octadeca-2E, 13Z-dienyl acetate, a pheromone component ofSynanthedon tipuliformis C., has been developed. The synthesis is based on cross-coupling of 8-iodooct-2E-en-I-ol THP ether with dec-5Z-enyl bromide catalyzed by CuBr. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1529–1531, August, 1997.     

Rapid synthesis of pomalidomide-conjugates for the development of protein degrader libraries

Current methods for the preparation of heterobifunctional pomalidomide-conjugates rely on methods that are often low yielding and produce intractable byproducts. Herein we describe our strategy for the reliable and succinct preparation of pomalidomide-linkers which is essential to the formation of these conjugates. We present the preparation of 18 pomalidomide-linkers in high yield compared to current literature methods. Our findings show that secondary amines consistently afford greater yields than their primary counterparts, a trend that we were able to exploit in the synthesis of several new pomalidomide homo-dimers in enhanced yields compared to similar literature syntheses. This trend was further utilised to develop the first one-pot synthesis of JQ1-pomalidomide conjugates in yields up to 62%, providing a method that is suited to rapid preparation of conjugate libraries as is frequently required for the development of new protein degraders.

Current methods for the preparation of heterobifunctional pomalidomide-conjugates rely on methods that are often low yielding and produce intractable byproducts. Herein we describe our strategy for the succinct preparation of pomalidomide-linkers.     

Trace Detection of Low Concentrations of Ozone Using a CO<Subscript>2</Subscript> Laser with Automatic Tuning over the Spectrum

A technique of detection of ozone, using a CO₂ laser with rapid automated tuning over 8–10 generation lines in the 9.4–9.6-µm spectral range, has been developed. Its experimental verification has shown a higher accuracy of detecting low concentrations of O₃ in comparison with the traditional technique of differential absorption on two lines (on-line and off-line). Using the technique suggested, the content of ozone in the vicinity of city roads with heavy traffic has been measured.__________Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 72, No. 2, pp. 251–255, March–April, 2005.     

Microwave-assisted scavenging of electrophiles utilizing polymer-supported sequestration reagents. Application to the synthesis of N3-acylated dihydropyrimidine libraries

Different scavenging techniques using polymer-supported sequestration agents are described for the purification steps in the synthesis of N3-acylated dihydropyrimidines. For scavenging both excess anhydride and unwanted byproducts, polystyrene and silica supported diamines, aminomethyl-functionalized SynPhase Lanterns and diethylenetriamine StratoSpheres Plugs are used. In both synthesis and purification microwave flash heating was utilized, reducing reaction times from hours to minutes. These two steps coupled with an efficient solid-phase extraction (SPE) workup allowed the generation of a 28-member library of N3-acylated dihydropyrimidines using anhydrides. Using related protocols a 15-member library of N3-functionalized dihydropyrimidines utilizing acid chlorides as acylating reagents was also obtained.     

New and efficient high Stokes shift fluorescent compounds: unsymmetrically substituted 1,2-bis-(5-phenyloxazol-2-yl)benzenes via microwave-assisted nucleophilic substitution of fluorine

Two new unsymmetric derivatives of 1,2-bis-(5-phenyloxazol-2-yl)benzene (ortho-POPOP) were synthesized via microwave-assisted nucleophilic substitution of fluorine which appears to be significantly more efficient compared with conventional thermal activation. The compounds synthesized are characterized by high fluorescence Stokes shifts (6000-11,000 cm⁻¹) in solvents of various polarity, intermediate-to-high fluorescence quantum yields and lifetimes in the range of several nanoseconds.     

Olefination of aldehydes with tetraalkyl-gem-dialumoalkanes

A new method of cis-olefination, based on the reaction of aldehydes with geminal alumolithium reagents, is proposed.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1151–1154, May, 1990.     

Reactions of 3-iodolevoglucosenone with sodium derivatives of some CH acids. Chiral cyclopropanes and stable oxetenes

3-Iodolevoglucosenone reacts with the sodium derivative of ethyl cyanoacetate at −60°C to give a tetrasubstituted cyclopropane derivative; similar reactions of the sodium derivatives of ethyl acetoacetate and acetylacetone at −60 °C afford the expected transformed Michael adducts, while at 20 °C,O,C-dialkylated products of the oxetene series are formed. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp 152–156, January, 1999.     

Avoiding the classical resolution during the synthesis of MeO-BIPHEP and 3,3′-disubstituted derivatives

The Ullmann coupling of 1 (R = H) gives a 2:1 mixture of diastereomers 2 (R = H) in 81% yield that are easily separated by silica gel chromatography. This procedure avoids the generally cumbersome and sometimes difficult resolution step with DBTA. Similar Ullmann couplings and separation of the corresponding diastereomers are employed with other derivatives of 1 (R = OtBu, iPr, Ph, and mesityl) ultimately affording a new series of 3,3′-disubsituted-MeO-BIPHEP derivatives. The use of these new derivatives in palladium-catalyzed asymmetric Heck reaction, Pd-catalyzed polyene cyclizations and rhodium-catalyzed hydrogenations is also reported.