Diethyl azodicarboxylate Subject

Coupling of excess (Z)-l,2-dichloroethene (217) with propargyl alcohol first led to the enyne 218, which, when subjected to a second Pd-catalyzed coupling step with trimethylsilylacetylene, provided the mixed diacetylene 219. With all carbon atoms assembled, the allene function was generated by first producing the (unprotected) hydrazine derivative 220, which on treatment with either diethyl azodicarboxylate (DEAD) or 4-methyl-l,2,4-triazoline-3,5-dione (MTAD) under anaerobic conditions at 0 °C yielded the hydrocarbon 27. According to mechanistic studies, the latter process leads first to a mixture of ( )- and (Z)-diazenes. Sigmatropic elimination of... 

In 2005, ot-benzylserine derivative [153] was reported to be converted into the (3-lactone using PPh3 and diethyl azodicarboxylate, giving an aza-peptide, which was then subjected to Mitsunobu conditions to afford the 3-benzyl-(3-lactam azapeptidomimetic (Scheme 61), [154]. 

Diethyl azodicarboxylate and triphenylphosphine permit the condensation between aldose derivatives with a free reducing centre and phenols. 2,3 5,6-Di-0-isopropylidene-D-mannose gave 67% of the phenyl o-D-mannofuranoside derivative and 16% of the /3-anomer, while 2,3 4,6-di-O-cyclohexylidene-a-D-mannose afforded access to p-nitrophenyl /3-D-mannopyranoside in 58% yield and other, substituted aryl analogues. Unsubstituted sugars can be subjected to the procedure, D-glucose giving mainly the phenyl 3-pyranoside. ... 

The highly substituted 5,6-dihydro-4//-l,3,4-oxadiazine (264 R = Pr") is formed as a by-product (20%) along with benzil monoxime (40%) on subjecting the O-benzylated monoxime of benzoin (PhCH(OH)C(Ph)=NOCH2Ph) to a Mitsunobu reaction (PhjP and diisopropyl azodicarboxylate) <87JOC4978>, Substitution of the diisopropyl by the diethyl ester raises the yield of oxadiazine (264 R = Et) to 50%,... 

---