Title of Addition of Ethyl Diazoacetate t Dimethylsorbate.

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Citation Bulletin of the Institute for Chemi University (1955), 33(6): 237-240 Issue Date

1 Studies on Synthetic Pyrethroids. ( Title Chrysanthemum-dicarboxylic Acid. (S of Addition of Ethyl Diazoacetate t Dimethylsorbate Author(s) Inouye, Yuzo; Ohno, Minoru Citation Bulletin of the Institute for Chemi University (1955), 33(6): Issue Date URL Right Type Departmental Bulletin Paper Textversion publisher Kyoto University

2 Studies on Synthetic Pyrethroids. (VI) Synthesis of Chrysanthemum-dicarboxylic Acid. (Supplement). Mechanism of Addition of Ethyl Diazoacetate to Ethyl a8-dimethylsorbate Yuzo INOUYE and Minoru OHNO (Takei Laboratory) Receivcsd November. 2, 1955 The mechanism of the addition of ethyl diazoacetate to sorbic acid esters is discussed. The possible intermediate pyrazoline and the stepwise decomposition thereof would be more reasonable for the elucidation of the formation of cyclopropane and acyclicompounds, as well as of cyclopropane products resulted from inversion of yr-ethylenic bond of asymmetrical sorbic esters during the addition of diazoacetate. As was reported in the previous paper,' ethyl diazoacetate (II) added predominantly to the r8-ethylenic bond of ethyl a8-dimethylsorbate (I) to give the geometrical isomers of naturally derived chrysanthemum-dicarboxylic acid, as well as an acyclic structural isomer (III) thereof under the conditions employed. The mechanism of the addition of aliphatic diazo-compounds to olefins remains uncertain, but the participation of free radicals is rather favoured at present. However, the formation of the acyclic structural isomer (III) of synthetic chrysanthemumdicarboxylic acid in our experiment (i) and the isolation of a pyrazoline intermediate) during the addition in one of the present reaction conditions favour the pyrazoline intermediate mechanism rather than free radical mechanism. Furthermore, Harper and Reed have recently isolated21 the cyclopropane derivative resulted from the addition of diazoacetate to methyl sorbate in which inversion of the ethylenic bond took place during the addition (iii), and two other similar cases in which inversion was confirmed, have been reported : that of the addition of dimethyl trans-but-2-ene-2,3-dicarboxylate" (iv), and of dimethyldiazomethane to ethyl maleate ' (v). Me2C=CH CH=C(Me)CO2Et > Me2C=C CH=C(Me)CO2Et IN2CHCO2Et i) IICH2 CO2Et III I > Mc2C CH CH=C(Me)CO2Et ii)ii\/ CH CO2Et IV c c iii) McCH=CH CH=CH CO2Me ---p VII ( 237 )

3 Synthetic Pyrethroids. (VI) CO2Et 1I ~H \ CH-Me Me /H CO2Et H / \ CH=CH CO2Me I/ NI/ \1 Me HH H VIVII MeCO2Me MeCO 2Me MeMe C=C >ii I.----_-_-.-I /\ Me0CMeMeOC\ a VIII\\I/ CH2N2/I\/1 1v) H /Me Me0_C\H/ CO2NIe H CO2Et HCO \ / HH IXX 2Et H H I v)etoccc\me CN2EtO2C\ H //HEtO2C \H //CO2Et XI\l\I HH XIIXIII From these evidences it seems probable that the addition of diazoacetate wotild not proceed by a simultaneous addition of the alkoxycarbonylme:hylene radical at both ends of the ethylenic bond, but proceed by stepwise process. In order to explain the formation of these products by the free radical mechanism, either cyclopropane intermediate or diradical should be postulated. Cyclopropane derivatives i.e. chrysanthemum-dicarboxylate in this case, are too rigid, as is well known, to be regarded as an intermediate which decomposes to give the acyclic compound (III) by ring fission, and to give rise to the inversion by intramolecular rearrangement. The assumption of successive occurrence of diradicals are thermodinamically not reasonable. The authors prefer the pyrazoline intermediate mechanism which could explain satisfactorily the formation of all these addition products mentioned above, one of the important evidences for which being the isolation of pyrazoline compound during the addition under one of the present reaction conditions. Although the structure of the pyrazoline intermediate isolated in our reaction (i) was not established, three following structures are theoretically possible s ys ys y =C---CH--=C CH =C--C-- I 11 1I II N C H H C N ---H C N \\/\%\/ NNNH abc Among these, 42-s`ructure c and 4'-structure b are excluded because these structures can not give rise to the acyclic isomer (III), in which the diazoacetate residue attaches to the r-carbon atom of the sorbate. By exclusion, 41-structure a is con- (238)

4 Yuzo INOUYE and Minoru OHN0 sidered to be that of the existing pyrazoline intermediate and this is also supported by the following scheme of formation : Me2C-CH CH=C(Me)CO2EtNCH Me2 C CH CH=C(Me)CO2Et -N =N CH CO2 Et -`ri XIV CO2Et This structure agrees with the fact that the pyrazoline gave no acetyl derivative. The intermediate pyrazoline dicarboxylic ester so formed (XIV) is postulated to decompose with expulsion of nitrogen to give the cyclopropane derivative (IV) in (ii), and similarly (VI) in (iii), (IX) in (iv), (XII) in (v) respectively : Scheme A. Me2C CH CH=C(Me) CO2 Et (X1V)-,I--r(IV) rrln NCH CO2Et ± N2 For the formation of acyclic isomer (III), the pyrazoline is postulated to decompose with migration of a hydrogen originally attached to r-carbon atom and expulsion of nitrogen as shown below : Scheme B. Me2 C C H CH -=--C(Me) CO2 Et (XIV) ---> > (III) + N2 in~ch CO2 Et N For the formation of the cyclopropane derivatives, in which inversion of the ethylenic bond occurs during the addition, the intermediate pyrazoline (XV), possibly formed by the same process as in the case of (XIV), is postulated to decompose with expulsion of nitrogen and inversion at 6-carbon atom as shown below : Scheme C. IIH Me tr' C CH CH=CH COZMe~Cy----CH Me~ - CH=CH CO2Et /11I--(VII) CH. CO2EtINCH CO2Et (XV) LAN~yyyyr -1-N2 The scheme of decomposition of the pyrazoline intermediate in each reaction would depend upon the reaction conditions employed. part V" The discussion is based on the experimental evidences described in the preceding The authors are indebted to Prof. S. Takei for his kind advice. ( 239 )

5 Synthetic Pyrethroids. (VI) REFERENCES (1) Inouye, Botys Kagaku, 20, 102 (1955). (1) Inouye, ibid. in press. (3) Harper, J. Chem. Soc (4) Auwers, Ann. 496, 252 (1932). (5) Guha, Ber. 70, 1688 (1937). (240 )

TitleSynthesis of Itaconic Acid from Eth. Author(s) Kunichika, Sango; Oka, Shinzaburo;

TitleSynthesis of Itaconic Acid from Eth Author(s) Kunichika, Sango; Oka, Shinzaburo; Citation Bulletin of the Institute for Chemi University (1966), 44(3): 221-225 Issue Date 1966-10-31 URL http://hdl.handle.net/2433/76124