Part I. Several 1,4-substituted bicyclo{2.2.0}hexanes are synthesized and their thermal isomerization to 1,5-hexadienes are studied. The (DELTA)(DELTA)G('+)'s of the substituted compounds (as compared to the parent bicyclo{2.2.0}hexane) are in good agreement with values of the radical stabilization energies of the substituents determined by other methods. The (DELTA)(DELTA)G('(NOT=)) value of a 1,4-disubstituted bicyclo{2.2.0}hexane is found to be a sum of the radical stabilization energies of the individual substituents in the 1 and 4 positions. The evidence supports a biradical intermediate in the ring opening of substituted bicyclohexanes. Finally, the 50.7 kcal/mole strain energy reported for a bicyclo{2.2.0}hexane moiety gives calculated values of (DELTA)H(,f) that agree to within (+OR-)3 kcal/mole of the experimental value, which has been determined by DSC. Part II. The thermal behavior of cis-dialkyldiazenes is studied by UV kinetics and their heat of isomerization to the more stable trans isomers is measured. The results support the semilinearization mechanism of isomerization for symmetric cis-dialkyldiazenes. Depending on structure, the cis diazenes are observed to isomerize, decompose, or undergo both process simultaneously. A kinetic isotope effect is observed for the reactive radicals obtained by thermolysis of cis-azo-1-adamantane and cis-azo-1-bicyclo{2.2.2}octane. The solvent cage effect is also determined.

Compound 593A and naphthyridinomycin are both naturally occurring antibiotics. They both have novel structural features which present challenges to the synthetic chemist. The first and, to date, only total synthesis of d,1-antibiotic 593A is described herein. A novel feature of this synthesis is the dimerization of an activated cis (alpha)-amino-(beta)-lactam to not only form the central piperazinedione but also to control four of the six asymmetric centers. Approaches toward the total synthesis of naphthyridinomycin, a novel quinone alkaloid, are also described. Interesting features include a cation-olefin cyclization to form a functionalized pyrrolidine and a proposed intramolecular attack of nitrogen on a quinone methide.

Three cyclopropyl substituted azoalkanes were synthesized: azocyclopropane, tert-butylazocyclopropane, and 1,1-dimethylallylazocyclopropane. Azocyclopropane was made by reducing azoxycyclopropane with Si(,2)Cl(,6) or LiAlH(,4). Both cis and trans isomers were extraordinarily stable azoalkanes. Heating the cis isomer (> 200(DEGREES)C) causes isomerization to the trans isomer and thermolysis of the trans isomer gives mostly diazavinylcyclopropane rearrangement. The activation enthalpy for this rearrangement suggests three electron stabilization of (alpha)-azoalkyl radicals. tert-Butylazocyclopropane was synthesized using a novel reaction sequence involving Me(,3)Al. Trans-tert-butylazocyclopropane underwent a diazavinylcyclopropane rearrangement when heated (217(DEGREES)C) to give the 2-pyrazoline in 84% yield. Heating the cis isomer results in 49% isomerization to the trans isomer and 51% nitrogen (radical products). The key step in the synthesis of 1,1-dimethylallylazocyclopropane involves a sigmatropic rearrangement of the 1,1-diazene resulting from the HgO oxidation of 1-(3,3-dimethylallyl)-1-cyclopropyl hydrazine. Irradiation of 1,1-dimethylallylazocyclopropane gave the "tail" recombination product ("turnaround product") of the cyclopropyldiazenyl and 1,1-dimethylallyl radicals. Turnaround product was also detected from the thermolysis of trans-1,1-dimethylallylazocyclopropane. The nitrogen quantum yield of 1,1-dimethylallylazocyclopropane was measured in two solvents of widely varying viscosity (pentane and hexadecane) and these quantum yields were used to estimate the fraction of the heminate radical pairs that underwent internal return or formed turnaround product. A series of progressively more symmetrical 1,1-dimethylallyl substituted azoalkanes was prepared. After irradiation (366 nm), turnaround product was detected (NMR, HPLC) from several of these compounds indicating that decomposition was occurring via a diazenyl radical. The decomposition rate constants for several diazenyl radicals were calculated using free energy differences of the appropriate symmetrical and unsymmetrical azoalkanes. Several schemes were proposed to rationalize the turnaround product results. The most favorable of these schemes indicates that internal return is an important rate influencing process in the decomposition of mechanism of azoalkanes.

Part I. Rates for the methyl rearrangement: ABPOMe (--->) ABMeP=O, A,B=Me,t-Bu, Et, Ph, OMe, OPh as catalyzed by methyl iodide (I), dimethyl sulfate (II), and methyl trifluoromethanesulfonate (III), were determined using proton and phosphorus NMR. Four distinct elementary steps for the rearrangement were found. Three correspond to a normal Arbuzov rearrangement, alkylation of the trivalent ester to yield the alkoxyphosphonium salt; followed by a reversible intramolecular decomposition of the intermediate to phosphonate and alkyl halide. The fourth step is the autocatalytic pathway: k(,3) ABMeP('+)OMe + ABPOMe (--->) ABMeP=O + ABMep('+)OMe With (I) as the catalyst k(,3) is insignificant, the reaction following the traditional two step mechanism. k(,3)'s importance when (II) is the catalyst depends upon the ligands A and B and also on concentration. (III) yields a purely autocatalytic mechanism except when A, B = PhO. LFE plots were constructed for the quaternization of phosphines and trivalent phosphorus esters using (I), (II), (III), and ethyl iodide. The observed lack of selectivity (constant (rho)(,I)) can be rationalized using a nonconcerted S(,N)2 displacement mechanism. Part II. Compounds of the type Poly-P('+)Ph(,2)OR ('-)OTf (IV) were synthesized from Amberlite XE-305. (IV), with R = primary alkyl, reacted with halogen and thiocyanate anions in CH(,2)Cl(,2) and Ch(,3)CN to yield alkyl halides and alkyl thiocyanates in yields comparable to those obtained for the monomeric analog. Dowex 50X2-200 and Amberlyst XN-1010 cation exchange resins were converted in high yields to the immobilized sulfonyl chloride form using PCl(,5) in o-dichlorobenzene at 110(DEGREES)C for 24 hrs. The sulfonyl chlorides reacted rapidly with amines and alcohols, to give sulfonate esters and sulfonamides. Conversion of Nafion (H('+)) to the sulfonyl chloride form using PCl(,5) was unsuccessful as were attempts to form the alkyl ester by treating Nafion (H('+)) with AgNO(,3) followed by RI, or CH(,2)N(,2) in ether.

Asparagusic acid is a naturally occurring 1,2-dithiolane that has been isolated from both the roots and edible portions of Asparagus plants (Asparagus officinalis L.). The substance is a plant growth inhibitor exerting activity comparable to abscisic acid. Asparagusic acid also possesses potent nematicidal activity. The mode of biosynthesis of the 1,2-dithiolane ring of lipoic acid suggests that asparagusic acid may be biosynthesized from isobutyric acid. {1-('14)C}Isobutyric acid was administered and found to be specifically incorporated into asparagusic acid. Doubly labelled forms of isobutyric acid were administered and the results show that Asparagus officinalis does not biosynthesize sulfur containing compounds via the same mechanism that is available to bacteria and fungi. Several sulfur containing compounds, {2-('3)H, 1-('14)C}-sodium 3-mercaptoisobutyrate, {('35)S, 3-('3)H}-sodium 3-mercaptoisobutyrate and {('35)S, 3-('3)H}S-(2-carboxy-n-propyl)-L-cysteine were synthesized and administered and the biosynthesis of asparagusic acid in Asparagus officinalis was determined.

Activation of ammonia and amines occurs during metal vapor synthesis at cryogenic temperatures. The Group IIA metal atoms: magnesium, calcium, strontium, and barium, and the transition metal atoms: chromium, manganese, iron, cobalt, nickel, and zinc react with amines and ammonia. Copper metal atoms do not react. Methane and hydrogen are evoved during warming of the Mn/(CH(,3))(,3)N matrix; methane is evolved during warming of the Mn/(CH(,3)CH(,2))(,3)N matrix. Hydrolysis of the cocondensates yields saturated and unsaturated hydrocarbons, and in some cases, hydrogen is formed. The reaction of certain cocondensates with unsaturated compounds yields hydrogenated products.

Rate constants for quenching of triplet sensitizers by several alkyl peroxides were measured by laser flash photolysis in benzene solution. Because these rate constants decrease monotonically with sensitizer triplet energy, electronic energy transfer is concluded to be the likely quenching mechanism. A rough correlation exists between quenching rate constants and peroxide thermal lability. Finally, the computer interfaced laser flash photolysis apparatus which was used in these measurements is described in detail.

An approach to the synthesis of the penicilium mold metabolite stipitatic acid has been investigated. It involved the preparation of a bis-(alpha)-diazoketone derived from citric acid, whose central (alpha)-hydroxy acid function had been masked and protected, and its conversion into a 6,6-disubstituted 2-cycloheptene-1,4-dione by intramolecular diazoketone coupling catalyzed by bis-cyclopentadienylnickel (nickelocene). Bromination of the enedione, followed by dehydrobromination, yielded a bromoenedione. (beta)-Elimination of both enediones with potassium hydroxide gave (gamma)-tropolones. Alakali treatment of the bromotropolone afforded a phenolic ring contraction product.

Methylenecyclopropene was generated under two different reaction conditions. The passage of 2-chloromethylenecyclopropane through a vertical column containing potassium t-butoxide supported on Chromosorb W (45/60 mesh) at 240(DEGREES)C and 10 mtorr produced methylenecyclopropene nearly free of impurities. The nuclear magnetic resonance spectra (('1)H and ('13)C) were obtained at -100(DEGREES)C in tetrahydrofuran-d(,8). The exocyclic protons appeared at (delta) 3.47 (t, J = 2.2 Hz) and the ring protons at (delta) 8.61 (t, J = 2.2 Hz). The exocyclic carbon appeared at (delta) 59.57 (t, ('1)J(,CH) = 161.5 Hz) and the ring carbons at (delta) 132.90 (t, ('1)J(,CH) = 228.5 Hz). The quaternary carbon was not observed. The infrared spectrum was obtained on an IBM Model 98 FTIR. The characteristic high energy transition appeared at 1770.3 cm('-1). These spectra indicate that 1a contributes significantly to the resonance hybrid. Methylenecyclopropene was also generated and trapped in a second flask as a Diels-Alder adduct when 2-bromomethylenecyclopropane was injected into a hot solution (75(DEGREES)C) of potassium t-butoxide in dimethyl sulfoxide and the volatiles trapped in a second flask containing cyclopentadiene. A series of aromatic gem-dichlorocyclopropanes, precursors to the cycloproparenes, were eliminated by potassium t-butoxide in dimethyl sulfoxide in the presence of methyl mercaptide. The major products were the (thiomethyl)methylaromatics. The failure to trap the expected cyclopropenes is seen as evidence of the reaction proceeding via a different mechanism in the higher homologs. This necessitated the development of a synthetic sequence in which the leaving groups were positioned at the bridge-head carbons. 1H-Cycloprop{b}anthracene was synthesized via this new synthetic sequence which involves the Diels-Alder reaction of 1-bromo-2-chlorocyclopropene. The treatment of 1a-bromo-9a-chloro-1a,2,9,9a-tetrahydro-1H-cycloprop{b}anthracene with potassium t-butoxide in tetrahydrofuran at -78 to -30(DEGREES)C afforded 1H-cycloprop{b}anthracene in 41.5% yield. The absence of unusual spectral properties (('1)H NMR, ('13)C NMR, UV, IR) indicates that it does not possess any great degree of bond fixation.

The biosynthesis of the antibiotic elaiomycin (1), produced by Streptomyces gelaticus, has been investigated. Precursor incorporation studies using (('13)C)- and {('3)H,('14)C}-labeled forms of serine have shown that carbons 2-4 of elaiomycin are derived from serine, with the hydroxymethyl carbon of serine being incorporated into C-4 of elaiomycin. An administration of (methyl-('13)C)-methionine has proven the methyl carbon of methionine to be the source of the O-methyl carbon of elaiomycin. (('13)C)- and {('14)C}-labeled precursor incorporation experiments indicate the novel introduction of C-2 of acetate into C-1 of elaiomycin. The administration of precursors labeled with contiguous ('13)C and ('15)N atoms has shown the oxygen-bearing nitrogen atom in elaiomycin to be derived from n-octylamine and the other nitrogen atom to be derived from serine.