Effect of changes in reaction conditions

The data in Table V indicate the gross effect of changes in reaction conditions on deoxygenation of the homologs in the -6(0)... 

The reaction of rhamnose and proline produces many pleasant aromas which are important to the food industry among them are bready, cracker-like and roasted aromas. These aromas are greatly influenced by changes in reaction conditions such as temperature, pH and the relative concentration of reactants (l.,2). The effects of changes in reaction conditions may be additive or synergistic. Research was undertaken to determine the prevalence and importance of synergies (variable interactions) between common reaction condition parameters for the reaction of rhamnose and proline. 

Table II. Effects of Changes in Reaction Conditions on the Quantity of Selected Volatiles (ppm)...

Studies on the alkaline hydrolysis of various phosphonic and phosphinic esters have provided information on the electronic or steric effects of substituents and the effects of changes in reaction conditions amongst the substrates so extensively examined are the O-aryl esters of dimethylphosphinothioic acid (552) esters of diphenylphosphinic acid and O-aryfand S -aryf esters of diphenylphosphinothioic acid (553 Z, Y = O or S). Other studies have concentrated on aryl esters of diaryIphosphinic acids (554) , and the effects of the stepwise replacement of P-Me by P-Ph in esters of dimethyl-, methylphenyl- and diphenyl-phosphinic acids The esters 555 (R = EtO, R = Me or Ph, R = R = Ph X = SEt or hydrolyse under alkaline conditions faster than do the comparable 5 -(4-substituted-butyl) esters. Comparable steric and electronic influences on the hydrolyses of phosphonic and phosphinic fluorides phosphinic chlo-rides the phosphonothioic chlorides 556 and other phosphonic and phosphinic esters have been noted. Phosphonic and phosphinic halides are prone to undergo halo-gen-exchange reactions, a process which, in general, is faster for derivatives of phosphonic than for those of phosphonothioic and phosphonoselenoic acids, and to be particularly important for acid fluorides . ... 

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