Penta-Aryl Derivatives of the Elements of the Fifth Group

By Prof. Dr. G. Wittig and Dr. D. Hellwinkel

Institut fur Organische Chemie der Universitat Heidelberg (Germany)

The synthesis of phosphorane derivatives by G. Wittig and E. Kochendorfer depends upon the reaction of triaryl- iminophosphorane derivatives with two equivalents of aryl- lithium [l]. It cannot be applied to the arsenic series since triphenylarsine and derivatives do not react with phenyl azide. It was established that the triphenyl-p-tolylsulphonylimine derivatives (I), which are prepared [2] by the reaction of chloramine-T with triphenylarsine and its analogues, can be converted in good yield to the penta-aryl compounds (11).

R3Y = NSOzC7H7 + 2 RLi + R3YR2' + Li2NS02C7H7 I I1

Y = P. As, Sb, Bi

A comprehensive publication will be prepared concerning the chemistry of bis(biphenyly1ene)phenylphosphoranes [I], -ar- soranes and -stiboranes.

Received December 12, 1961 [Z 181/4 IEI

[ l ] G . Witfig and E. Kochendorfer, Angew. Chem. 70, 506 (1958). [2] F. G. Mann and E. L. Chaplin, J. chem. SOC. (London) 530, 535 (1937).

Synthesis of Nicotine, Myosmine and Pyridylproline[*]

By Prof. Dr. H. Hellmann and Dr. Dieter Dieterich

Chemisches Institut der Universitat Tubingen (Germany)

In the hydrolysis of (I), obtained from nicotinoyl acetic ester, paraformaldehyde and acetaminomalonic ester by asym- metrical three - carbon condensation, 2-(P-pyridyl)- A2-pyrro- line-5-carboxylic acid (11) is formed. This can be converted into the tobacco smoke alkaloid, myosmine (111), by de- carboxylation and into 5-(b-pyridyl)proline (IV) by hydro- genation.

COiR

!IJ-C02H

I1

4-COZ

r --, -7

r--1

Compound (IV) can be methylated with formaldehyde/formic acid to 5-(p-pyridy1)hygrinic acid (V) which splits off C02 on heating with the formation of nicotine (VI). Total yield: 20 % based on nicotinoyl acetic ester. 5-(y-Pyridyl)proline can be prepared analogously in 60 % total yield.

Received December 14, 1961 [Z 184/20 IE]

[*] "AsymmetricalThree-CarbonCondensations ; XIII". PartXII : H. Hellmann and M . Schrcder, Liebigs Ann. Chem., in the press.

Rearrangement of a Cyclopropane Derivative into a Heterocyclic Seven-Membered Ring Compound

By Prof. Dr. Emanuel Vogel and Dip1.-Chem. Rolf Erb

Institut fur Organische Chemie der Universitat Koln (Germany)

cis-l,2-Divinylcyclopropane isomerizes even as it is formed (80 "C.), undergoing a Cope rearrangement to form cyclo- heptadiene-(1,4) [l], while the trans isomer is converted to cycloheptadiene-(1,4) only when heated to 190 "C. since it does not fulfil the steric prerequisites for the cyclic transition state of the Cope rearrangement [2]. These results suggest that cyclopropane compounds which are derived from cis-l,2- divinylcyclopropane by replacing a vinyl group with another double bond function, for example, -N=C=O, :C=N- or :C=O, should be capable of undergoing an isomerization analogous to the Cope rearrangement. The reaction of diazoacetic acid ethyl ester (1 mole) with excess butadiene (6 moles) at 100-1 10 'C. (8 hours) yields 80 % 2-vinylcyclopropane carboxylic acid ethyl ester (I), cis: trans = 45 : 55. The mixture was converted into cis- and trans- 2-vinylcyclopropane carboxylic acid azide (11) and the azides were subjected to Curtius degradation at 80°C. in benzene. Two products with the composition C6H70N were formed: a solid substance 0, m.p. 48-50 'C. (32 % relative to the total quantity of isomeric acid chloride), and a liquid (VI), b.p. 85-86OC./165 mm. Hg; ng = 1.4630 (33 %).

1) NaOH

COOCZHS NzCH-COOC~H~ \ .\

CON3

(cis and trans) (cis and trans)

I I1

111 Iv

VI V

The IR spectrum of (V) shows a lactam-like amide group as well as conjugated C=C-bonds, but no vinyl group, and thus points to an unsaturated seven-membered lactam. This was verified by catalytic hydrogenation: (V) absorbs 2 moles of hydrogen with platinum in acetic ester and is converted to caprolactam. The position of the double bonds in the lactam were proven by the IR and UV data (Amax = 255 mp; log e = 3.69 in methanol), as well as by the nuclear magnetic resonance spectrum (adjacency of the CHz-group to the carbonyl group). The substance thereby recognized as 1-azacyclohepta-4,6- diene-Zone (V) is apparently formed by valence isomeri- zation of the thermolabile cis-2-vinylcyclopropyl isocyanate

53 Angew. Chem. internat. Edit. / Vol. I (1962) / No. 1