Dicarboxylic acids glycols, cyclic

Silver/silver oxide Carboxylic acids from glycols Dicarboxylic acids from cyclic glycols... 

Molybdenyl acetoacetonatejiQYi-butyl hydroperoxide Dicarboxylic acids from cyclic glycols s. 44, 247... 

Regioselectivity of C—C double bond formation can also be achieved in the reductiv or oxidative elimination of two functional groups from adjacent carbon atoms. Well estab llshed methods in synthesis include the reductive cleavage of cyclic thionocarbonates derivec from glycols (E.J. Corey, 1968 C W. Hartmann, 1972), the reduction of epoxides with Zn/Nal or of dihalides with metals, organometallic compounds, or Nal/acetone (seep.lS6f), and the oxidative decarboxylation of 1,2-dicarboxylic acids (C.A. Grob, 1958 S. Masamune, 1966 R.A. Sheldon, 1972) or their r-butyl peresters (E.N. Cain, 1969). 

So far, various dicarboxylic acid derivatives, dicarboxylic acids, their activated and non-activated esters, cyclic acid anhydrides, and polyanhydrides have been polymerized with glycols through lipase catalysis to give polyesters. 

A novel chemoenzymatic route to polyester polyurethanes was developed without employing highly toxic isocyanate intermediates. First, diurethane diols were prepared from cyclic carbonates and primary diamines, which were subsequently polymerized with dicarboxylic acids and glycols by using lipase CA as catalyst, yielding the polyurethanes under mild reaction conditions. 

Various combinations of dicarboxylic acid derivatives and glycols enzymatically afforded polyesters under mild reaction conditions. Dicarboxylic acids as well as derivatives, activated and non-activated esters, cyclic acid anhydride, and polyanhydrides, were found to be useful as monomer for the enzymatic synthesis of polyesters. 

The oxidation of cyclic alkenes by Cr(VI) reagents can be a useful method for formation of dicarboxylic acids. The initial oxidation step appears to yield an epoxide, which then undergoes solvolytic ring opening to a glycol or glycol monoester, which is... 

Lipase-Catalyzed Polymerization of Dicarboxylic Acids or Their Derivatives. Enzymatic synthesis has been achieved via various combinations of dicarboxylic acid derivatives and glycols. As to the diacid monomer, dicarboxylic acids, activated and nonactivated esters, cyclic acid anhydrides, and polyanhydrides were enzymatically reacted with glycols under mild reaction conditions. 

Ethylene glycol brassylate cyclic diester Ethylene undecane dicarboxylate Tridecanedioic acid cyclic ethylene glycol diester 1,13-Tridecanedioic acid, 1,2-ethanediol ester 1,13-Tridecanedioic acid ethylene ester... 

Dicarboxylic add cyda a cyclic pathway (Fig.) which enables the utilization of glyoxylic acid or one of its precursors (e.g. glycolic acid) as a carbohydrate source for the growth of microorganisms. The D.c.a. includes some of the reactions of the tricarboxylic add cycle. It also involves malate synthase (EC 4.1.3.2 see Glyoxylate cycle). If the concentration of D.c. a. interm iates is too severely reduced by diversion to synthetic pathways, they can be replenished from the Glycerate pathway (see). 

---