3. J. P. Hazel, C. M. Weeks, and Y. Dsawa, Cryst. Struct. Commun., No. 5, 103 (1976). 4. S. V. Lindeman, Yu. T. Struchkov, A. M. Turuta, et al., Bioorg. Khim., 13, 252 (1987). 5. A. M. Turuta, A. V. Kamernitskii, S. V. Lindeman, et al., Izv. Akad. Nauk SSSR, Ser.

Khim., 1109 (1986). 6. V. M. Tseikinskii, V. B. Rybakov, V. I. Simonov, et al., Bioorg. Khim~ 6, 752 (1980). 7. A. M. Turuta, L. Kohout (Kogout), S. V. Lindeman, et al., Izv. Akad. Nauk SSSR, Ser.

Khim., 333 (1985). 8. S. S. Batsanov, Structural Refractometry [in Russian], Vysshaya Shkola, Moscow (1976),

p. 92. 9. G. E. Maciel and G. V. Savitsky, J. Phys. Chem., 69, 3925 (1965).

i0. L. Kohout, A. Kasal, V. Sando, and H. Velgova, Collect. Czech. Chem. Commun., 48, 173 ( 1 9 8 3 ) .

11. J . W. B l u n t and J . B. S t o t h e r s , O r g . Magn. R e s o n . , 439 ( 1 9 7 7 ) . 12 . J . B. L a m b e r t a n d A. R. V a g e n a s , Org . Magn. R e s o n . , 270 ( 1 9 8 1 ) . 13. A. V. K a m e r n i t s k i i a n d A. M. T u r u t a , Usp . K h i m . , 1516 ( 1 9 8 2 ) . 14. A. V. Kamernitskii (Kamernitzky), A. M. Turuta, I. N. Fundieler, et al., Tetrahedron,

3--8, 165 ( 1 9 8 2 ) . 15. A. V. Kamernitskii, A. M. Turuta, and Ngo TkhiMai An, Izv. Akad. Nauk SSSR, Set. Khim.,

924 (1980).

NMR INVESTIGATION OF SOME a,w-DISUBSTITUTED FARNESANES

I. M. Avrutov, N. Ya. Grigor'eva, V. S. Bogdanov, and A. M. Moiseenkov

UDC 543. 422.25:547.394'26:547.289.1

In continuation of our work on the synthesis of polyprenols by means of controlled aldol condensation we have prepared a series of farnesane stereoisomers (I-V) [I, 2]. Stereochemical monitoring of the reaction course was carried out spectroscopically, the most informative method being a3C NMR. The data in this report are of intrinsic interest and can lead to structural assignments in the indicated compounds.

\ \ !~' \

{1) (If) (IiI)

HII

(iv)

2Z, 8Z, R = C02Et (Ia)--(Va); 2E, 6Z, R = C02Et (Ib)--(Vb);

2Z, 6E, R = CQEt (Ic)--(Vc);

2E, 6E, R : C02Et (Id)--(Vd).

(v)

2Z, 6Z, R = CH2OCH2Ph (Ie)--(Ve); 2E, 6Z, tt = CH20CH2Ph (If )--( Vf);

I 1 2Z. roZ, R = (CH2)3CHOCH2CH20 (Ig)--(Vg )

f - - t 2E, 6Z, I{ = (CH~)aCHOCH2CH~0 (Ih)--(Vh)

We have achieved an essentially unambigous assignment of the 13C NMR spectra of (I-V) (Table i) based on previously reported data, in particular for the isomeric farnesyl esters (Ia-d) and related compounds [3]. When compared with (I) the spectra of (II-V) showed new signals in the regions 25-40 and 55-80 ppm. The latter was assigned to C I~ and C 11 on the basis of a partially proton decoupled (PPD) experiment. Assignment of the higher field triplets (using PPD) to C s and C 9 was made on the basis of the nearly identical molecular environments for C 9 in the 6Z- and 6E-isomers of (II-V) leading to very similar chemical shifts (CS). By con- trast, the different environments for C s should lead to markedly different CS for (II-V) isomers. The validity of these assignments was confirmed by calculation~of Cs for C s and C 9 for (II)

N. D. Zelinskii Institute of Organic Chemistry, Academy of Sciences of the USSR, Moscow. Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. i0, pp. 2194-2198, October, 1987. Original article submitted March 20, 1986.

0568-5230/87/3610-2033512.50 �9 1988 Plenum Publishing Corporation 2033

to

cD

oo

&-.

TABLE

i.

laC NMR Spectra of (l

-V)

13

14

15

T:~

X

Y9

8

5 4

R

t i

i I

{o I

R:~

CO

OE

t (

a-d

),

R=

CH

2OC

H~

Ph

(e,

f),

II:C

HI(

CH

.)zC

HO

--C

H2

CH

(g

, h)

*

Ch

emic

al s

hift

of

atom

C n

pp

m

Com

poun

d t

2 3

~ 5

6 7

8 11

12

13

14

15

2Z, 6

Z

(Ia)

(K

a)

I IIIa

) IV

a)

(Va)

2E, 6

Z

(Ib)

(I

Ib)

(rob

) (I

Vb)

(V

b)

2Z, 6

E

(Ie)

(I

~c)

(me)

(:

vc)

(vc)

2E, 6

E

(Id)

(I

Id)

(III

d)

(IV

d)

(Vd)

2Z

, 6Z

(Ie)

(V

e)

2E, 6

Z

(If)

(V

f)

2z, 6

z (ig

) (v

g)

2E,

6Z

(Ih)

l llh)

ll:h)

(Vh)

166,

3 t6

6,4

166,

2 t6

5,9

t65,

4

t67,

0 t6

6,6

166,

4 t6

6,7

16~,

4

t65,

8 t6

6,0

166,

0 16

6,3

165,

6

167,

0 16

6,9

t66,

5 f6

7,2

t66,

8

66,5

66

,2

66,6

66

,4

27,6

27

,6

27,9

27

,7

27,'~

27

,~

tt6,

6 tt

6,4

tt6,

6 1t

6,2

116,

6

t16,

0 11

5,9

t 16,

0 11

5,7

t15,

7

t16,

9 1t

6,7

1t6,

6 1t

6,4

t16,

5

tt6,

2 tt

6,1

1t5,

4 tt

5,5

115,

4

t22,

t t2

2,1

t2t,

2 12

t,2

124,

3 12

5,3

124,

4 **

t2

4,5

t24,

5 12

4,6

160,

2 i6

0,2

t59,

7 t5

9,9

158,

8

t59,

7 t5

9,1

t58,

9 t5

9,2

t58,

7

159,

5 t5

9,2

t 59,

4 t5

9,5

t58,

8

t59,

7 t5

9,3

t.58,

9 15

9,7

t59,

0

t38,

4 13

8,5

t38,

5 13

8,5

t35,

1 **

t3

5,0

t35,

0 t3

5,t

f35A

13

5 0

33.9

33

,8

33.7

34

,t 33

.6

4t.5

41

,2

40,9

41

,0

40,7

33,7

33

,3

33,3

33

,2

32,3

4t,3

40

,9

40,6

40

,8

40,5

32,6

32

,2

39,9

39

,4

3t,9

**

3 L

9

40,2

40

,1

40,0

39

,8

26,9

26

.8 *

26

,7

26,6

25

.2

26.2

26

,3

25.7

25

.8

25,7

27.1

26

,7

26,7

26

.5

26.4

26,3

*

26,4

25

,8

25,9

25

,8

26.5

26

.3

26.3

25

,9

26.t

~ 26

.3

26.7

26

.2

26.5

26

,5

124,

7 t2

6,0

125,

2 12

4,8

t25,

7

124,

t 12

5,4

t24,

1 t2

4,2

t24,

9

t24,

1 t2

5,t

124,

2 t2

3,9

125,

5

123,

3 t2

4,8

123,

4 12

3,5

t23,

9

t24,

4 **

12

5,8

124,

5 **

12

5,9

125,

0 **

t2

6,5

124,

6 **

12

6,9

125,

9 12

6,6

t35,

8 t3

4,4

135,

0 t3

5,7

133,

9

136,

2 t3

4,4

135,

0 '1

35,8

t3

3,9

t35,

7 t3

3,9

134,

8 13

5,5

133,

6

t36,

4 13

4,5

t35,

t t3

6,0

134,

ti

t35,

6 t3

3,3

t35,

3 13

3,0

135,

3 t3

2,7

135,

4 13

3,3

134,

0 13

3,C

32,1

30

,6

28,5

28

,7

24,2

32,2

30

,6

28,4

28

,8

24,2

40,1

38

,2

36,3

36

,6

3t,6

40,0

38

,2

36,2

36

,6

3t,6

32,0

24

,t

32,0

24

,1

'*

32,2

**

24,3

32,t

30,6

28

,6

24,4

9 1o

124,

7 69

,9

64,0

77

,6

t99,

2

24,5

70

,1

63,7

78

,t 42

.0

20t,3

27.t

t24,

9 32

,t 69

,9

27,5

63

,9

29.7

77

,9

41.9

20

0,4

27.0

**

t24,

6 32

A

69,8

27

,4

63,5

29

,8

78,0

4t

,9

20t,6

26,7

**

t24,

7 **

42

,1

20t,5

265

**

t24,

8 **

41

,9

201,

4

26,3

**

125,

2 **

42

,3

201,

6

26,8

t2

5,2

32,2

69

,9

27,5

64

,0

42,4

20

1,8

26.9

32

:5

27.6

29

,9

42,3

26,8

32

.2

27.2

'2

9.7

~3~1

,4 72

,5

58,2

72

,5

t31,

9 72

.4

58.0

72

.9

131.

0 72

.3

57.9

72

.9

13ts

72

15

57.(~

72

,9

t31,

4

131,

3

131.

3

t31,

4 72

A

58.1

~7,7

'.6

,0 *

* 18

,8

.)3,6

**

17,~

26

,'1 *

~

231~

*"

t7,!

26

,~

t8,~

23

,: *:

~7,!~

26

,(' *

' 18

,~

23,~

t7,6

17,6

t7.5

t7,7

26

,2 *

* 18

,8

5,0

~.6,8

**

).4,9

!6

,t **

.)5,9

26

,3 *

* ~4

,7

26,4

**

25,9

26

,4

24,8

26

,2 *

*

25,9

26

,4 *

* 24

,6

23,3

25,6

25,6

25,5

25,7

26

,6 *

* 25

,0

23,6

23

,3

23,3

23

,3

23,t

23,5

23

,1

23,1

23

,2

22,8

t6,2

t5

,9

t6,0

15

,8

t5,8

16,2

15

,8

15,9

15

,9

t5,9

23,3

22

,8

23,3

22

,8

23,3

22

,9 *

*

23,4

23

,3

23,3

23

,t

25~9

25

,3

25,3

25

:3

25,2

t8,9

t8

.9

t8fi

18

,8

18,6

25,5

25

,t 25

,2

25,0

24

,9

t9,0

18

,8

i8fl

t8

,7

18,5

23,4

23

,3

i6,5

i6

~3

23~3

23

,2 *

*

t6,0

i6

,0

i6,0

t6

,0

*The spectra of (la-d) to

(Va-d) also showed signals for OC2H~ groups,

(le,

f) to

(Ve,

f) showed signals for CsHsCH= and

l I

(Ig, h)

to (Vg, h)

the group (CIr~hC~OC~=CH20

**Pairs of close-together signals may be exchanged.

TABLE 2. Calculated CS Values (6, ppm) for C s and C 9 in Com- pounds II, IV, and VI

Compound 6 r 6 c~ Compound 6 c~ 6 c~

(IIa, b) (IIc, d) (IVa, b) (IVc, d)

29,3 37,9 2L2 35,8

31,1 31,3 28,7 28,9

(Via) (VIb)

31,.~ 40,0

24,9 25A

and (IV) according to an additive scheme using the Grant and Paul formula [4]* for 6,7,10,11- tetrahydro-(I). Increments were introduced into this molecule for A~-cis and A6-trans double bonds (i.e., giving 6Z/6E-10,11-dihydrofarnesyl esters (Via, b) [6])as well as Br at C l~ and OH at C 11 and C I~ [7]. The results obtained (Table 2) were very satisfactorily correlated with the experimental data for 6E-compounds (IIc, d; IVc, d) but a little worse for the 6Z- isomers (IIa, b; IVa, b). Further, in the latter case the higher field signal corresponded to C 8 (cf. Table i).

The calculated CS for C s and C 9 in (Via, b) (Table 2) were compared with the experimental- ly found values for (IIIa-d) (see Table i). It was thus possible to work out mean increment values (absent in the literature) for the epoxide C a and C B atoms as +2.5 and -3.4 ppm respectively.

Especially notable from analysis of data in Table i was the effect of functionalization in (Ia-d) on the CS of the rather remote CI-C 5 atoms of the primary isoprene unit, being most marked (i.0 to -1.4 ppm) for the 6Z-aldehydes (Va, b). Moreover, there was a clear, inverse effect of the stereochemistry of the isoprene unit on the CS of C l~ which was shifted to low field by 1.2-1.9 ppm for the 2E-(V) relative to the 2Z-isomers. The effect was also a max- imum for the 6Z isomers. It can be looked on as a new, independent confirmation of the hypothesis of twist conformational contributions for the approach of primary and tertiary isoprene monomer units in sesqui- and diterpenes. This had been previously proposed for a study of intramolecular epoxidation of farnesol and geranylgeraniol ethers [8] and for some behavioral aspects of (Ia, d) and (Va, d) under conditions of dissociative electron capture [9] and polarography [i0]. Support to this is given by measurement of the nuclear 0verhauser effect (NOE) for (Ia-d), (Va-d). In fact, saturation of the resonance for the protons of the cis CH~-C II group in (Ia) led to a 0.3% NOE increase for H-C 2. An analogous 0.2% NOE increase for H-C2 was rioted when the resonances of the cis CHs-C II in (Ib) and (Id) and the cis and trans CH3--C :t and CH3--C 7 in (Ic) were saturated. Information concerning the approach of the individual partsof the isoprene chain as a result of its folding up was also ob- tained for aldehydes (Vb, d), viz., saturation of H-~ 2 gave an NOE increase of 0.2% for al- dehyde protons, 0.3% for If-C ~ in (Vb) and 0.2% for H--C 6 in (Vd).

EXPERIMENTAL

For the synthesis of (Ia-d) to (Va-d) see [ll], (IIe-Ve) see [i], and (IIf-h) to (Vf-h) see [2]. 13C NMR spectra (in CDCI 3) were recorded on Bruker WP-60 (15.08 MHz) and Bruker WM 250 (62.89 MHz) instruments and NOE studies on the latter using the TOE method [12]. The pulse delays were: t I = 0.5 sec, t 2 = 0.8 sec, t 3 = 0.005 sec, for i0,000 to 12,000 scans. Difference spectra were recorded. The signal/noise ratio for the inverted difference signal with the fine structure of the starting signal was 25-50; after ~i000 scans the intensity of this sig- nal increased by ten times, tending to zero.

CONCLUSIONS

New, independent evidence for the twisted conformation of linear isoprenoid molecules has been obtained from a study of the ~3C NMR spectra of the ethyl ester isomers of ll-bromo- 10-hydroxy, 10,11-epoxy, and 10,11-dihydroxy-3,7,11-trimethyldodeca-2E/Z, 6E/Z-dienecarboxylic

*The Grant and Paul formula [4] and not the more exact Lindeman and Adams formula [5] was used since, with its aid [6, 7], increments had been calculated for functional substituents by comparison of experimental data for the appropriate parent alkanes and their derivatives. In agreement with [4, 7] the value B = 194.9 ppm (from CS2) was taken. Since a value of B = 196 ppm was used in [6] the increments for olefinic atoms from [6] were taken with a corre- tion of +i.i ppm (from CS 2) or -i.i ppm (on the 6 scale).

2035

acids when compared with the corresponding ethyl esters of 3,7,11-trimethyldodeca-2E/Z,6E/ Z,10-trienecarboxylic acid (farnesyl ester). Further information came from an NOE study of the latter and the ethyl esters of 10-formyl-3,7-dimethyldeca-2E,6E/Z-dienecarboxylic acid.

LITERATURE CITED

i. A. V. Semenovskii, N. Ya. Grigor'eva, I. M. Avrutov, et al., Izv. Akad. Nauk SSSR, Ser. Khim., 152 (1984).

2. N. Ya. Grigor'eva, I. M. Avrutov, O. A. Pinsker, et al., Izv. Akad. Nauk SSSR, Ser. Khim., 1824 (1985).

3. A. S. Shashkov, N. Ya. Grigor'eva, I. M. Avrutov, et al., Izv. Akad. Nauk SSSR, Ser. Khim., 388 (1979).

4. D. M. Grant and E. G. Paul, J. Am. Chem. Soc., 86, 2984 (1964). 5. L. P. Lindeman and J. Q. Adams, Anal. Chem., 43, 1245 (1971). 6. D. E. Dorman, M. Joutelat, and J. D. Roberts, J. Org. Chem., 36, 2757 (1971). 7. G. Engelhardt, E. Lippmaa, and T. Penk, J. Prakt. Chem., 312, 935 (1970). 8. R. Breslow and L. M. Maresca, Tetrahedron Lett., 887 (1978). 9. I. I. Furlei, V. N. Odinikov, V. I. Khvostenko, et al., Izv. Akad. Nauk SSSR, Ser. Khim.,

330 (1981). i0. S. G. Mairanovskii, G. K. Bishimbaeva, N. Ya. Grigor'eva, et al., Izv. Akad. Nauk SSSR,

Ser. Khim., 2703 (1979). ii. N. Ya. Grigor'eva, I. M. Avrutov, A. V. Semenovskii, et al., Izv. Akad. Nauk SSSR, Ser.

Khim., 382 (1979). 12. G. Wagner and K. Wuthrich, J. Magn. Resonance, 33, 675 (1979).

ELECTRONIC STRUCTURE OF NEGATIVE MONOTHIOCARBONATE IONS

A. V. Pogulyai, V. I. Khvostenko, S. M. Kalashnikov, R. F. Mavlyutov, and U. B. Imashev

UDC 543.51:541.124.7:547.279.1

A number of monothiocarbonates (MTC): RZSC(O)OR 2, where R I, R 2 = CH 3, C2H 5, CsH 7, i-C3HT, n-C4H 9 CH2=CHCH2, have been studied by negative ion (NI) resonance electron capture (REC) mass spectrometry and photoelectronic (PE) spectroscopy.

The analysis of the data in the PE spectra of the compounds (Table i) permits concluding that the higher occupied molecular orbital (HOMO) is the orbital of the unshared electron pair (UEP) of the S atom, which is confirmed by SCF LCAO MO quantum chemical calculations in the MNDO and CNDO valence approximation [i]. The second band in the PE spectrum corre- sponds to the UEP of the carbonyl O atom according to the calculations, which is in agreement with the conclusions in [2]. For interpreting the third band, we will examine the inductive effect of the alkyl substituents with fixed R I = CH s and variable R 2. In the series of these compounds, the third ionization potential (IP s) varies from 11.24 to 10.8 eV in substitution of the methyl group at the ester O atom by an isopropyl or n-butyl group, which is in agree- ment with the values of the Taft o constants OMe = 0.0, oi_Pr = -0.19, On_Bu = -0.13. The results of the calculations also indicate that the third HOMO is an antibonding combination of the UEP of the ester and carbonyl O atoms with a larger contribution from the ester O atom. Note that IP 2 varies from 10.5 to 10.2 eV, while IP I is even weaker: from 9.51 to 9.35 eV, which confirms the interpretation of the first three IP.

It should be noted that in S-allyl- and O-ethyl-MTC, the second band is double with re- spect to the integral intensity and the vC= C orbital enters into it in addition to the UEP of the carbonyl O atom.

The basic processes of decomposition of the molecular NI (MNI) (Table 2) primarily take place with direct bond rupture, and the maximum lines in the spectrum correspond to rupture

Department of Physics and Mathematics, Bashkir Branch, Academy of Sciences of the USSR; Ufim Petroleum Institute. Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. i0, pp. 2198-2202, October, 1987. Original article submitted March 7, 1986.

2036 0568-5230/87/3610-2036~$12.50 �9 1988 Plenum Publishing Corporation