Claisen rearrangements based on vinyl fluorides

Journal of Fluorine Chemistry 125 (2004) 1593–1608

www.elsevier.com/locate/ﬂuor

Claisen rearrangements based on vinyl ﬂuorides

*

Frank Tranel, Gu¨nter Haufe

¨ ¨ ¨ ¨

Organisch-Chemisches Institut, Westfalische Wilhelms-Universitat Munster, Corrensstr. 40, D-48149 Munster, Germany

¨

Dedicated to Professor Gerd-Volker Roschenthaler on the occasion of his 60th birthday.

Available online 13 November 2004

Abstract

2-Fluoroalk-1-en-3-ols (4), available from terminal alkenes (1) by bromoﬂuorination, subsequent dehydrobromination of the 1-bromo-2-

ﬂuoroalkanes (2) to form 2-ﬂuoroalkenes (3) and selenium dioxide mediated allylic oxidation with tert-butylhydroperoxide, undergo

Johnson-Claisen rearrangement on treatment with trimethyl orthoacetate to give methyl 4-ﬂuoroalk-4-enoates (7) in high yields. In contrast

Ireland-Claisen rearrangement of 3-acetoxy-2-ﬂuorodec-1-ene (9b) with triethylamine and TMSOTf in ether failed. Instead of the expected

formation of a carboxylic acid, selective C-silylation of the a-position to the carboxyl group to form 14 occurred. However, Ireland-Claisen

rearrangement was successful with corresponding chloroacetates 10 and propionates 11 of four 2-ﬂuoroalk-1-en-3-ols (4) to give 2-chloro-4-

ﬂuoroalk-4-enecarboxylic acids (15) or its 2-methyl derivatives 16, respectively, in moderate yields. These [3,3]-sigmatropic rearrangements

are diastereoselective giving trans-conﬁgured double bonds, exclusively. Corresponding esters derived from (Z)-2-ﬂuorocyclododec-2-enol

(22), did rearrange to yield mixtures of diastereomers much less selectively. Also 2-ﬂuorodec-2-enol (6), which was prepared by

rearrangement of 2-ﬂuoro-2-octyloxirane (5) with TMSOTf and triethylamine, was successfully applied as a starting material for [3,3]-

sigmatropic rearrangements. The corresponding 3-(1-ﬂuoroethenyl)alkanoic acid derivatives 17 and 18 were formed in moderate yield.

Keywords: Fluorinated allylic esters; Vinyl ﬂuorides; [3,3]-Sigmatropic rearrangement; Claisen rearrangement; Stereochemistry; Carboxylic acid derivatives

1. Introduction

[11,12]), the Reformatsky [13,14], the ester enolate [15–

17], and the Ireland-Claisen rearrangements [18–20] should

be mentioned as some of the synthetically most useful

variants regularly applied with non-ﬂuorinated compounds.

Many examples of sigmatropic rearrangements with

polyﬂuorinated compounds have also been described [21–

23]. Among others there are Ireland-Claisen rearrangements

with terminal diﬂuorinated allylic esters [23–25], Johnson-

Claisen rearrangements of allylic alcohols with terminal

diﬂuorinated double bonds [24–28], and Claisen rearrange-

ments of polyﬂuorinated allylvinyl ethers [29–35]. In

contrast, there is a relatively small number of examples

for rearrangements with monoﬂuorinated oleﬁns. As early as

in 1988 a one-pot cascade reaction of a Claisen and

subsequent Cope-rearrangement of a vinyl ﬂuoride was

described [36].

Rearrangement reactions belong to the most frequently

applied transformations of carbon skeletons in organic

synthesis. Besides the Cope-rearrangement and its variants,

the classical Claisen-rearrangement of allylphenyl ethers

and particularly the aliphatic Claisen-rearrangements gained

a very important position [1,2]. These reactions proceed as

symmetry-allowed suprafacial thermal [3,3]-sigmatropic

rearrangements through the lowest energy chair-like, six-

membered transition states [3–5]. This allows to predict the

stereochemistry of the formed main product. Most

importantly, from the synthetic point of view, there were

developed plenty of variants of this type of rearrangement.

By way of example, the Carroll [6,7], the Johnson [8], the

Eschenmoser [9,10] (including the Overman variant

As a typical example for a classical aromatic Claisen

rearrangement, a ﬂuorinated analogue of the anti-malaria

agent Bialamicol was synthesized from a ﬂuorinated

* Corresponding author. Tel.: +49 251 833 3281; fax: +49 251 833 9772.

E-mail address: haufe@uni-muenster.de (G. Haufe).

doi:10.1016/j.jﬂuchem.2004.09.001

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F. Tranel, G. Haufe / Journal of Fluorine Chemistry 125 (2004) 1593–1608

Scheme 1.

Scheme 3.

Scheme 2.

allylphenyl ether in the presence of p-dimethylamino

pyridine (DMAP) (Scheme 1) [37].

Different examples of Johnson-Claisen rearrangements of

2-ﬂuoroallylic alcohols by treatment with triethyl orthoace-

tate or triethyl orthopropionate in hot phenol leading to the

corresponding ethyl esters have been published by Allmen-

dinger et al. These transformations yielded 42–74% of the

corresponding esters (Scheme 2) [38].

Scheme 4.

m-chloroperbenzoic acid. Epoxidation of vinyl ﬂuorides has

been described earlier by Elkik and Le Blanc [50] and

Schlosser and Michel [51,52]. On the other hand it is known

that non-ﬂuorinated allylic alcohols can be prepared from

epoxides by deprotonation of the 3-position with strong

bases such as LDA or KO^tBu through an E1cb mechanism

[53]. Applying these and several similar conditions to the

ﬂuorinated epoxide 5 led to complicated mixtures of many

ﬂuorinated and non-ﬂuorinated compounds in all cases.

Alternatively, ring opening of epoxides by treatment with

electrophiles such as butyldimethylsilyl iodide [54] or

trimethylsilyl triﬂuoromethane sulfonates [55] in the

presence of weak bases such as triethylamine has been

described. Under the conditions shown in Scheme 5, the

epoxide 5 was rearranged to 6 in low yield.

Analogously, several examples of Johnson-Claisen

rearrangements involving 3-ﬂuoroalk-2-enol derivatives

have been published by Percy and coworkers [28,39] and

similar reactions were used as key-step in syntheses of

nucleosides [40–42].

In the frame of our interest in synthetic applications of

vinyl ﬂuorides, we discovered a simple and efﬁcient access

to 2-ﬂuoroallylic alcohols some years ago consisting of

bromoﬂuorination of terminal alkenes [43,44], dehydro-

bromination of the formed 1-bromo-2-ﬂuoroalkanes [45–

47] and SeO₂-mediated allylic oxidation [48]. Now we

investigated the application of these ﬂuorinated allylic

alcohols in different types of Claisen rearrangements.

The mechanism of this reaction is not clear yet, but it is

known that silyl iodides or silyl triﬂates with tertiary amines

form ammonium salts, which are less active silylation

reagents [56,57]. Probably these Lewis acids can activate the

2. Results and discussion

Our well-established three-step sequence [47] of bromo-

ﬂuorination of 1-alkenes 1, leading to 92:8 mixtures of 1-

bromo-2-ﬂuoroalkanes 2 and its regioisomers, HBr-elim-

ination from the bromoﬂuorides and selective allylic

oxygenation of the vinyl ﬂuorides 3 provided the desired

ﬂuorinated allylic alcohols 4a–4c in 25–43% overall yield

(Scheme 3). 2-Fluoroallylic alcohol (4d) was prepared from

ammonium 2-ﬂuoroacrylate (Scheme 4) [49].

Another ﬂuorinated primary allylic alcohol, 2-ﬂuorodec-

2-enol (6), was prepared from the epoxide 5, which was

accessible from 2-ﬂuorodecene (3b) by epoxidation with

Scheme 5.

F. Tranel, G. Haufe / Journal of Fluorine Chemistry 125 (2004) 1593–1608

1595

Scheme 6.

Table 1

Results of Johnson-Claisen rearrangement of ﬂuorinated allylic alcohols 4

Scheme 8.

Alcohol

R¹

Ester

Yield (%)

4a

4b

4c

4d

C₃H₇

7a

7b

7c

7d

96

84

81

0

The corresponding propionates 11 were synthesized by

treatment of 4 with propanoic acid in the presence of DCC/

DMAP (method B) similarly to a protocol independently

described by Neises and Steglich [59] and Hassner and

Alexanian [60].

C₇H₁₅

C₁₃H₂₇

H

Similarly, also 2-ﬂuorodec-2-enol (6) was acylated with

chloroacetic anhydride in the presence of pyridine and a

catalytic amount of DMAP or with propanoic acid/DCC/

DMAP to give the corresponding chloroacetate 12 or the

propionate 13, respectively (Scheme 9).

At the beginning of our investigations only two examples

[36,39] of Ireland-Claisen rearrangements of allylic acetates

bearing a vinylic ﬂuorine were described in literature. All

our attempts towards rearrangement of 9b under classical

conditions of Ireland [19] failed and besides the starting

material only complex mixtures of products were formed.

oxirane, which in the absence of nucleophiles is opened and

subsequently deprotonated in the b-position. The thus-

formed silylether could not be isolated, but acidic hydrolysis

led to the desired allylic alcohol 6. All attempts to increase

the yield of this reaction failed until now.

Having several ﬂuorinated allylic alcohols in hand, we

investigated Johnson-Claisen rearrangements of these

compounds. Thus, the ﬂuoroallylic alcohols 4a–4c were

reﬂuxed with trimethyl orthoacetate in toluene in the

presence of a catalytic amount of propionic acid for 5 h to

give the corresponding trans-conﬁgured methyl 4-ﬂuoroalk-

4-enecarboxylates 7a–7c in good to excellent yields

(Scheme 6, Table 1). In contrast, compound 4d did not

give any of the expected ester under these conditions and

heating with the orthoester in the absence of a solvent was

unsuccessful as well. The reasons for this failure are not

clear yet.

Also under the conditions of

a thermodynamically

controlled enolization [61,62] the expected product of the

Ireland-Claisen rearrangement was not formed. However,

under these conditions a selective C-silylation of the a-

carbon to the carbonyl group to form the a-silylated ester 14

was observed, though the transformation was not complete

(Scheme 10).

Under standard conditions, the reaction of 2-ﬂuorodec-2-

enol (6) with trimethyl orthoacetate was very slow (6%

conversion of 6 after reﬂuxing in toluene for 6 h). Therefore,

compound 6 was reﬂuxed in neat triethyl orthoacetate for 5 h

to give the rearrangement product 8 in 39% yield (Scheme

7). Elongation of the reaction time led to side reactions and

did not improve the yield. Steric reasons and the formation

of a less stable terminal double bond might be responsible

for the low yield of the latter reaction.

Such a-silylations were already observed in literature,

particularly when TMSOTf was used instead of TMSCl [63].

Though, several Ireland-Claisen rearrangements have been

described [18,19], this type of reactions seem not generally

to be possible with acetates and several failures of such

The ﬂuorinated allylic alcohols 4 were subsequently

esteriﬁed by treatment with acetic anhydride or chloroacetic

anhydride, in the presence of DMAP (method A) according

Scheme 9.

¨

to a protocol developed by Steglich and Hoﬂe [58] to

give the corresponding esters 9, 10 or 11, respectively

(Scheme 8).

Scheme 7.

Scheme 10.

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F. Tranel, G. Haufe / Journal of Fluorine Chemistry 125 (2004) 1593–1608

Scheme 11.

Table 2

Synthesis of ﬂuorinated allylic esters and 4-ﬂuoroalk-4-enecarboxylic acid derivatives

Alcohol

R¹

R²

X

Allylic ester (method)

Yield (%)

Carboxylic acid

Yield (%)

a

4b

4a

4b

4c

4d

6

4a

4b

4c

4d

6

C₇H₁₅

C₃H₇

C₇H₁₅

C₁₃H₂₇

H

9b (A)

91

79

92

95

84

99

68

90

74

50

94

–

0^a

29

54

66

86

60

32

70

72

5

H

Cl

10a (A)

10b (A)

10c (A)

10d (A)

12 (A)

11a (B)

11b (B)

11c (B)

11d (B)

13 (B)

15a

15b

15c

15d

17

16a

16b

16c

16d

18

H

Cl

H

Cl

H

Cl

H

C₇H₁₅

H

Cl

C₃H₇

C₇H₁₅

C₁₃H₂₇

H

Me

H

C₇H₁₅

52

a

Ethyl ester formed by Johnson-Claisen rearrangement.

reactions have been mentioned in literature [26]. Since the

corresponding carboxylic esters are available by Johnson-

Claisen rearrangement, these investigations were not

continued.

competing deprotonation in b-position to the ﬂuorine

substituent with strong bases. A comparable observation

was made by Percy et al. in rearrangements of Ireland-

Claisen systems bearing a g-ﬂuorine substituent [39].

Therefore, we used another method of enolization acting

under less basic conditions and leading to the (Z)-enolate

under thermodynamic control. Thus, treatment of the esters

11 or 12 with TMSOTf and triethylamine at room

temperature in dichloromethane for 4 days gave the

expected 4-ﬂuoroalk-4-enecarboxylic acids 15 or 16 bearing

a chlorine or a methyl substituent in 2-position in reasonable

yields (except compound 16d) (Scheme 11, Table 2).

From investigations of the crude product mixtures by GC

and ¹⁹F NMR spectroscopy it became obvious that the

reaction, after >80% conversion of starting material yielded

Furthermore, the esters 10 and 11 substituted by chlorine

or a methyl group in a-position to the carboxyl function

were treated with LDA and TMSCl using the classical

conditions of Ireland-Claisen rearrangement at À78 8C.

However, no rearrangement products were found after

warming the reaction mixture to room temperature. The

esters were partially recovered besides the allylic alcohols 4

produced by ester hydrolysis. Similar ester hydrolyses

initiated by silylation reagents have already been observed

for other types of reactions by Emde and Simchen [61].

Another reason for the failure of rearrangement might be a

Scheme 12.

F. Tranel, G. Haufe / Journal of Fluorine Chemistry 125 (2004) 1593–1608

1597

exclusively the rearranged products 15 or 16, respectively.

The moderate yields are due to difﬁcult isolation and

puriﬁcation of the products, which were partially destroyed

during chromatographic separation (vide infra). Thus,

the Ireland-Claisen rearrangement gave the (Z)-conﬁgured

4-ﬂuoroalk-4-enecarboxylic acids. This stereochemistry

becomes obvious from the big vicinal coupling constant

³J_H,Fof 37–38 Hz in the ¹H NMR spectra of compounds 15

and 16.

The formation of these diastereomers can be rationalized

from the most probable transition state I (Scheme 12). The

alternative, II, with an axial R substituent is much less

probable. This type of stereocontrol was already described

by Ireland et al. [19].

The carboxylic acids 15b or 16b were treated with

methanol in the presence of DCC/DMAP to give the

corresponding methyl esters in 86 or 67% yield, respec-

tively.

Ireland-Claisen rearrangement of substituted carboxylic

esters of the primary allylic alcohol 2-ﬂuorodec-2-enol,

namely the reactions of the chloroacetate 12 and the

propionate 13 under the same conditions gave mixtures of

diastereomers in 60 or 52% yield, respectively. Thus, from

12 a 1:1 mixture of compounds 17 was formed, while the

rearrangement of 13 led to a 81:19 mixture of the

diastereomers 18. These diastereomers were not separated

(Scheme 13, Table 2).

Scheme 14.

Scheme 15.

This type of an Ireland-Claisen rearrangement was much

less efﬁcient starting with a cyclic vinyl ﬂuoride derived

from (E)-cyclododecene (19) by bromoﬂuorination and

subsequent HBr-elimination from the formed cis-1-bromo-

2-ﬂuorocyclododecane (20) to form (E)-1-ﬂuorocyclodode-

cene (21). The allylic oxidation with selenium dioxide and

tert-butylhydroperoxide occurred selectively in b-position

to the ﬂuorine substituent to give the (Z)-conﬁgured allylic

alcohol 22 in low yield. The alcohol was esteriﬁed under the

conditions described above to give the esters 23 or 24 in

good yield.

chromatography was difﬁcult and led to partial loss of

material. When about 10% of acetic acid was added to the

eluent, the vinyl moiety of compound 16b was partially

solvolyzed. We have shown earlier that this function is

sensitive against strong acids [48]. Thus, the ester 11b was

rearranged according to the general procedure and the crude

reaction product was subjected to column chromatography

(silica gel) using a mixture of cyclohexane, ethyl acetate and

acetic acid (10:1:1) as an eluent. In this way 2-methyl-4-

oxododecanoic acid (27) was isolated in 45% overall yield

(Scheme 15).

Ireland-Claisen rearrangement under the above-men-

tioned standard conditions gave the corresponding carboxylic

acids 25 or 26 in about 60% yields (GC) as about 70:30

mixtures of diastereomers (Scheme 14). The isomers could

neither be separated from each other nor from the starting

materials. Moreover, the formation of double bond isomers

could not be excluded.

3. Conclusion

It has been mentioned already that puriﬁcation of the

4-ﬂuoroalk-4-enecarboxylic acids 15 and 16 by column

Based on vinyl ﬂuorides 3 and 21 a series of ﬂuorinated

allylic alcohols 4, 6 and 22 has been synthesized. Reﬂuxing

the allylic alcohols 4 or 6 with trimethyl- or triethyl

orthoacetate in toluene Johnson-Claisen rearrangement

occurred providing high-yielding access to (Z)-4-ﬂuoroalk-

4-enecarboxylic esters 7 or 8, respectively. In agreement with

the behaviour of non-ﬂuorinated allylic acetates, also

ﬂuorinated analogues such as 3-acetoxy-2-ﬂuorodec-2-ene

(9b) seem not to be suitable to undergo Ireland-Claisen

rearrangement on treatment with triethylamine and TMSOTf

at room temperature. Under these conditions, C-silylation of

Scheme 13.

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F. Tranel, G. Haufe / Journal of Fluorine Chemistry 125 (2004) 1593–1608

the a-position to the carbonyl group occurred. On the other

hand, a-substituted acetates such as the a-chloroacetates 11

or the propionates 12 rearranged under the same conditions to

give the corresponding 2-substituted (Z)-4-ﬂuoroalk-4-enoic

acids15or 16in moderateyields. The esters 23and 24derived

from (Z)-2-ﬂuorocyclododec-2-enol (22) under similar

conditions gave mixtures of diastereomers in low yield.

The ﬂuorovinylic moiety is hydrolysed to the keto group

under acidic conditions.

4.2.2. 1-Bromo-2-ﬂuorodecane (2b)

According to the general procedure 2b was prepared from

1b (14.00 g, 0.1 mol). Yield: 22.76 g (95%) (contaminated

with 8% of the regioisomer and 3% of the 1,2-dibromide).

The spectroscopic data agree with those published in Ref.

[46].

4.2.3. 1-Bromo-2-ﬂuorohexadecane (2c)

According to the general procedure 2c was prepared from

1c (22.40 g, 0.1 mol). Yield: 31.93 g (99%) (contaminated

with 8% of the regioisomer and 3% of the 1,2-dibromide).

¹H NMR (CDCl₃): d 0.88 (t, ³J_H,H= 6.9 Hz, 3 H, 16-CH₃),

1.26 (m, 22 H, 5-CH₂–15-CH₂), 1.35–1.55 (m, 2 H, 4-CH₂),

4. Experimental

4.1. General remarks

1.60–1.80 (m, 2 H, 3-CH₂), 3.46 (dd, ²J_H,H= 5.0 Hz, ³J_H,F

=

2

19.6 Hz, 2 H, 1-CH₂), 4.61 (dm, J_H,F= 47.7 Hz, 1 H, 2-

CHF). ¹³C NMR (CDCl₃): d 14.1 (q, C-16), 22.7 (t, C-15),

24.7 (dt, ³J_C,F= 3.8 Hz, C-4), 29.2–29.8 (t, C-5–C-13), 31.9

NMR spectra were recorded at 300 MHz (¹H), 75 MHz

(¹³C) and 282 MHz (¹⁹F) and are reported in ppm downﬁeld

from TMS (¹H and ¹³C, CDCl₃as internal standard, d =

77.0 ppm), or CFCl₃(¹⁹F). Mass spectra were recorded by

GC/MS coupling (EI, 70 eV) or by GC/MS/CI (chemical

ionization). Gas chromatographic analyses were performed

using a column HP-5 (30 m, Ø0.32 mm, ﬁlm 0.25 mm, carrier

gas N₂) or SPB-1 (30 m, Ø0.32 mm, ﬁlm 0.25 mm, carrier gas

N₂). Thin-layerchromatography was done oncoated silicagel

plate Merck 60 F₂₅₄. Column chromatography was done with

silica gel Merck 60 (0.063–0.2 mm). All reactions involving

air-sensitive agents were conducted under argon atmosphere

applying Schlenk-technique. All reagents purchased from

suppliers were used without further puriﬁcation. CH₂Cl₂was

dried and distilled over P₂O₅, toluene was dried by azeotropic

distillation, followed by distillation over sodium. Solvents for

chromatography were distilled prior to use.

2

(t, C-14), 33.3 (dt, J_C,F= 16.5 Hz, C-3), 33.7 (dt, J_C,F

=

1

21.6 Hz, C-1), 92.1 (dd, J_C,F= 175.5 Hz, C-2). ¹⁹F NMR

(CDCl₃) d À178.0 (m). GC/MS (70 eV): m/z (%) 324/

322 (0/0) [M⁺], 304/302 (1/1) [M⁺À HF], 276/274 (1/1), 241

(1) [M⁺À HBr À H], 189 (2) [M⁺+ H À HF À HBr], 163 (7),

111 (13) [C₈H₁₅⁺], 97 (57) [C₇H₁₃⁺], 85 (33) [C₆H₁₃⁺], 83

(55) [C₆H₁₁⁺], 71 (56) [C₅H₁₁⁺], 69 (45) [C₅H₉], 57 (100)

+

[C₄H₉], 55 (54) [C₄H₇], 43 (88) [C₃H₇], 41 (45) [C₃H₅].

+

4.3. Dehydrobromination of bromoﬂuorides

4.3.1. 2-Fluorohex-1-ene (3a)

In a two-necked ﬂask with a distillation bridge powdered

KOH (13.00 g, 232 mmol) was treated drop wise with the

mixture prepared in Section 4.2.1 (13.00 g, 63 mmol of 2a)

and heated to 95 8C until the formed vinyl ﬂuoride 3a

distilled completely (4–48 h depending on the particle size

of KOH). Yield: 5.27 g (82%, based on the part of 2a

contained in the starting material). The spectroscopic data

agree with those published in Ref. [65].

4.2. General procedure for bromoﬂuorination

A solution of 100 mmol of the corresponding terminal

1 and triethylamine trihydroﬂuoride (25 mL,

alkene

153 mmol) in CH₂Cl₂(100 mL) under stirring at 0 8C

was treated in portions with NBS (21.9 g, 120 mmol). The

mixture was stirred overnight while warming up to room

temperature. The yellowish suspension was poured into ice

water (500 mL) and treated with a conc. ammonia solution

until the pH was signiﬁcantly basic. The aqueous phase was

extracted with pentane (3 Â 150 mL). The combined organic

layer was washed with 2N HCl (2 Â 150 mL) and with 5%

NaHCO₃-solution (3 Â 150 mL) and water (150 mL). After

removing of the solvent the residue can be puriﬁed by

column chromatography. Generally, the crude product was

used for the next step.

The corresponding bromoﬂuoride 2 (50.0 mmol) in

pentane (500 mL) was reﬂuxed with potassium tert-

butanolate (6.74 g, 60 mmol) for 5 h. The mixture was

poured into water (500 mL), the phases were separated and

the organic layer was washed with water (200 mL) and 5%

aqueous NaHCO₃solution (200 mL). After drying of the

organic phase over MgSO₄, the solvent was removed and the

crude product was puriﬁed.

4.3.2. 2-Fluorodec-1-ene (3b)

The mixture from 4.2.2 (22.49 g, 94 mmol) was reﬂuxed

with potassium tert-butanolate (12.63 g, 113 mmol) in

pentane (1200 mL) for 5 h. The mixture was poured into

water (1000 mL), the phases were separated and the organic

layer was washed with water (200 mL) and 5% aqueous

NaHCO₃solution (200 mL). After drying of the organic

phase over MgSO₄, the solvent was removed and the crude

product was distilled. Yield: 9.58 g (65%, mixture of 85%

3b, 12% dec-1-yne, 3% of 1-ﬂuorodecene, 69% yield of 3b

4.2.1. 1-Bromo-2-ﬂuorohexane (2a)

According to the general procedure 2a was prepared from

1a (8.40 g, 0.1 mol). Yield: 17.65 g (96%) (contaminated

with 8% of the regioisomer and 4% of the 1,2-dibromide).

The spectroscopic data agree with those published in

Ref. [64].

F. Tranel, G. Haufe / Journal of Fluorine Chemistry 125 (2004) 1593–1608

1599

based on 2b). b.p. 71 8C at 27 mbar (Lit.: 95 8C at 133 mbar

[48]). The spectroscopic data agree with those published in

Ref. [46].

4.4.1. 2-Fluorohex-1-en-3-ol (4a)

Compound 3a (9.30 g, 91 mmol) was reacted according

to the general procedure. Due to the volatility of the product

a different work-up was necessary. After completion of the

reaction the mixture was treated with pentane (300 mL) and

diethyl ether (90 mL). The organic phase was washed with

10% KOH (4 Â 80 mL) and with a sat. NaCl solution

(30 mL). After drying the solvent was evaporated and the

residue was distilled. Yield: 7.00 g (65%). b.p. 33–35 8C at

80 mbar. ¹H NMR (CDCl₃): d 0.95 (t, ³J_H,H= 7.4 Hz, 3 H, 6-

CH₃), 1.44 (m, 2 H, 5-CH₂), 1.65 (m, 2 H, 4-CH₂), 1.83 (br s,

4.3.3. 2-Fluorohexadec-1-ene (3c)

Similar to the above-mentioned procedure 3c was

prepared from pure 2c (16.12 g, 50 mmol). Yield: 12.50 g

(mixture of 72% 2c, 23% 1-bromohexadec-1-ene, 2%

hexadec-1-yne). ¹H NMR (CDCl₃): d 0.88 (t, ³J_H,H= 6.9 Hz,

3 H, 16-CH₃), 1.26 (m, 22 H, 5-CH₂–15-CH₂), 1.50 (m, 2 H,

3

4-CH₂), 2.17 (m, 2 H, 3-CH₂), 4.17 (dd, J_H,F= 50.3 Hz,

1 H, OH), 4.13 (ddd, ³J_H,H= 5.7 Hz, ³J_H,H= 7.2 Hz, ³J_H,F

2

12.9 Hz, 1 H, 3-CH), 4.52 (dd, J_H,H= 3.1 Hz, J_H,F

=

²J_H,H= 2.4 Hz, 1 H, 1-CH₂), 4.47 (dd, ³J_H,F= 17.4 Hz, ²J_H,H

= 2.4 Hz, 1 H, 1-CH₂). ¹³C NMR (CDCl₃): d 14.1 (q, C-16),

22.7 (t, C-15), 26.0 (t, C-4), 28.9, 29.4, 29.5, 29.6, 29.7 (t, C-

5–C-13), 31.9 (dt, ²J_C,F= 28.0 Hz, C-3), 31.9 (t, C-14), 89.1

(dt, ²J_C,F= 21.6 Hz, C-1), 167.1 (d, ¹J_C,F= 256.9 Hz, C-2).

3

2

3

49.6 Hz, 1 H, 1-CH₂), 4.65 (dd, J_H,H= 3.1 Hz, J_H,F

17.8 Hz, 1 H, 1-CH₂). ¹³C NMR (CDCl₃): d 13.7 (q, C-6),

18.4 (t, C-5), 36.1 (t, C-4), 70.1 (dd, ²J_C,F= 30.5 Hz, C-3),

90.0 (dt, ²J_C,F= 17.8 Hz, C-1), 166.9 (d, ¹J_C,F= 259.4, C-2).

3

¹⁹F NMR (CDCl₃): d À95.0 (ddt, J_H,F= 17.2 Hz, J_H,F

=

¹⁹F NMR (CDCl₃): d À111.8 (ddd, ³J_H,F= 11.5 Hz, ³J_H,F

=

3

17.2 Hz, J_H,F= 51.5 Hz). GC/MS (70 eV): m/z (%) 242

(0.2) [M⁺], 222 (4) [M⁺À HF], 180 (7) [M⁺À HF À C₃H₆],

166 (6) [180 À CH₂], 152 (7) [180 À C₂H₄], 152 (6) [180 À

C₃H₆], 138 (8) [180 À C₄H₈], 125 (11), 124 (9) [180 À

C₅H₁₀], 110 (22) [180 À C₆H₁₂], 96 (64) [180 À C₇H₁₄], 85

(16) [C₆H₁₃⁺], 82 (100) [180 À C₈H₁₆], 71 (35) [C₅H₁₁⁺], 69

17.2 Hz, ³J_H,F= 49.6 Hz). GC/MS (70 eV): m/z (%) 118 (1)

[M⁺], 103 (2) [M⁺À CH₃], 90 (8) [M⁺+ H À C₂H₅], 76 (25)

[C₃H₅OF⁺], 75 (100) [C₃H₄OF⁺], 71 (14), 55 (11) [75 À

+

HF], 43 (58) [C₃H₇], 41 (47) [C₃H₅].

+

(84) [C₅H₉], 57 (88) [C₄H₉], 55 (81) [C₄H₇], 43 (100)

+

[C₃H₇], 41 (62) [C₃H₅].

+

4.4.2. 2-Fluorodec-1-en-3-ol (4b)

According to the general procedure 4b was prepared from

9.42 g (59.6 mmol) 3b. The product 4b was puriﬁed by

column chromatography with cyclohexane/ethyl acetate

(10:1). Yield: 4.87 g (47%). The spectroscopic data agree

with those published ones [48].

4.3.4. (E)-1-Fluorocyclododecene

Similar to the procedure mentioned above, (E)-1-

ﬂuorocyclododecene (21) was prepared from diastereopure

cis-1-bromo-2-ﬂuorocyclododecane (20) [43,44] (13.25 g,

50.0 mmol) by reﬂuxing with KO^tBu (11.23 g, 100 mmol) in

cyclohexane (650 mL) for 5 h. Yield: 9.02 g (98%). The

spectroscopic data agree with published ones [66].

4.4.3. 2-Fluorohexadec-1-en-3-ol (4c)

According to the general procedure 4c was prepared from

10.0 g (29.8 mmol) 3c. The product 4c was puriﬁed by

column chromatography with cyclohexane/ethyl acetate

(10:1). Yield: 4.25 g (55%). m.p. 30 8C (pentane). ¹H NMR

(CDCl₃): d 0.88 (t, ³J_H,H= 6.9 Hz, 3 H, 16-CH₃), 1.26 (m, 22

H, 5-CH₂–15-CH₂), 1.54–1.76 (m, 2 H, 4-CH₂), 1.90 (br s, 1

4.4. General procedure for the allylic oxygenation of vinyl

ﬂuorides with selenium dioxide

A solution of selenium dioxide (5.55 g, 50 mmol) and

80% tert-butyl hydroperoxide in di-tert-butyl ether (25 mL,

200 mmol) in CH₂Cl₂(100 mL) was treated with the

corresponding ﬂuoroleﬁn 3 (20 mmol) and acetic acid

(2.3 mL, 40 mmol). Subsequently, the mixture was stirred

for 4–14 days at room temperature. Then toluene (10 mL)

was added to precipitate SeO₂, which was separated. Then

CH₂Cl₂was removed without heating in vacuo. The residue

was dissolved in diethyl ether (20 mL) and the solution was

washed with 10% aqueous KOH (4 Â 10 mL) in order to

separate remaining SeO₂. To reduce the excess peroxide the

solution was stirred with 5 g of FeSO₄Á7H₂O at room

temperature for 4 h. The colored suspension was ﬁltered and

the residue was washed with diethyl ether. The solution was

washed with 2N HCl (20 mL) and with a sat. NaCl solution

(30 mL). The solution was dried with MgSO₄and the

solvent was evaporated. The crude product was puriﬁed by

column chromatography.

H, OH), 4.10 (dddd, ⁴J_H,H= 0.5 Hz, ³J_H,H= 5.8 Hz, ³J_H,H

=

3

7.6 Hz, J_H,F= 13.1 Hz, 1 H, 3-CH), 4.52 (ddd, J_H,H

4

3

2

0.5 Hz, J_H,F= 49.4 Hz, J_H,H= 3.1 Hz, 1 H, 1-CH₂), 4.64

(dd, ³J_H,F= 17.4 Hz, ²J_H,H= 3.1 Hz, 1 H, 1-CH₂). ¹³C NMR

(CDCl₃): d 14.1 (q, C-16), 22.7 (t, C-15), 25.1 (t, C-5), 29.4,

29.5, 29.6, 29.7, 31.9, 34.0 (t, C-4 and C-6–C-14), 70.3 (dd,

²J_C,F= 31.9 Hz, C-3), 90.0 (dd, ²J_C,F= 18.0 Hz, C-1), 166.8

1

(d, J_C,F= 260.8 Hz, C-2). ¹⁹F NMR (CDCl₃): d À111.7

(ddd, ³J_H,F= 13.4 Hz, ³J_H,F= 17.2 Hz, ³J_H,F= 49.6 Hz). GC/

MS (70 eV): m/z (%) 258 (1) [M⁺], 240 (1) [M⁺À H₂O], 211

(11) [240 À C₂H₅], 182 (2) [C₁₃H₂₆⁺(McLafferty)], 166 (4),

137 (5), 114 (12), 113 (8) [C₈H₁₇⁺], 99 (9) [C₇H₁₅⁺], 97 (20)

[C₇H₁₃⁺], 86 (36), 85 (19) [C₆H₁₃⁺], 83 (25) [C₆H₁₁⁺], 76

(69) [C₃H₅OF⁺], 75 (75) [C₃H₄OF⁺], 71 (40) [C₅H₁₁⁺], 69

+

(36) [C₅H₉], 57 (88) [C₄H₉], 55 (50) [C₄H₇], 43 (100)

+

[C₃H₇], 41 (55) [C₃H₅]. Calcd. for C₁₆H₃₁FO (258.24): C

74.37, H 12.09. Found: C 74.76, H 12.53.

1600

F. Tranel, G. Haufe / Journal of Fluorine Chemistry 125 (2004) 1593–1608

4.4.4. (Z)-2-Fluorocyclododec-2-en-1-ol (22)

clear solution was stirred overnight while warming to room

temperature. Then 2N HCl (150 mL) was added at room

temperature and stirring was continued for 4 h. The layers

were separated and the aqueous phase was extracted with

CH₂Cl₂(2 Â 50 mL). The combined organic phases were

washed with 2N HCl (2 Â 100 mL) and a 5% NaHCO₃-

solution (100 mL) and dried over MgSO₄. The solvent was

removed in vacuo and the product was puriﬁed by column

chromatography (cyclohexane/ethyl acetate, 10:1). Yield:

720 mg (25%). ¹H NMR (CDCl₃): d 0.87 (t, ³J_H,H= 6.7 Hz, 3

H, 10-CH₃), 1.20–1.43 (m, 10 H, 5-CH₂–9-CH₂), 1.65 (s, 1

According to the general procedure 22 was prepared from

(E)-1-ﬂuorocyclododec-1-en (21) (7.00 g, 38 mmol). After

50% conversion of 21 the crude product was puriﬁed by

column chromatography (cyclohexane/ethyl acetate, 10:1)

to give a 92:8 mixture of 22 and its (E)-isomer. Yield: 1.96 g

(27%). ¹H NMR (CDCl₃): d 1.08–1.62 (m, 14 H, 5-CH₂–11-

CH₂), 1.65–1.82 (m, 2 H, 12-CH₂), 1.90–2.10 and 2.30–2.43

=

3

(m, 2 H, 4-CH₂), 2.16 (s, 1 H, OH), 4.10 (ddd, J_H,H

3

4.5 Hz, J_H,H= 9.5 Hz, J_H,F= 21.7 Hz, 1 H, 1-CH), 4.84

(ddd, ³J_H,H= 6.2 Hz, ³J_H,H= 9.5 Hz, ³J_H,F= 37.2 Hz, 1 H, 3-

3

CH). ¹³C NMR (CDCl₃): d 22.2 (dt, J_C,F= 3.8 Hz, C-4),

22.9, 24.0, 24.7, 25.4, 25.7, 25.8 (t, C-5–C-11), 31.9 (t, C-

H, OH), 2.10 (dt, J_H,H= 6.9 Hz, J_H,H= 6.9 Hz, 2 H, 4-

CH₂), 4.10 (d, ³J_H,F= 15.7 Hz, 2 H, 1-CH₂), 4.83 (dt, ³J_H,H

=

2

3

12), 71.7 (dd, J_C,F= 30.5 Hz, C-1), 108.8 (dd, J_C,F

=

7.5 Hz, J_H,F= 37.2 Hz, 1 H, 3-CH). ¹³C NMR (CDCl₃): d

14.0 (q, C-10), 22.6 (t, C-4), 23.3 (t, C-9), 29.0–29.1 (3 t, C-

5–C-7), 31.7 (t, C-8), 61.4 (dt, ²J_C,F= 30.5 Hz, C-1), 108.1

(dd, ²J_C,F= 12.7 Hz, C-3), 157.5 (d, ¹J_C,F= 254.3 Hz, C-2).

1

14.0 Hz, C-3), 158.2 (d, J_C,F= 255.6 Hz, C-2). ¹⁹F NMR

(CDCl₃): d À129.3 (m). GC/MS (70 eV): m/z (%) 201 (2)

[M⁺+ H], 200 (3) [M⁺], 183 (1) [M⁺+ H À H₂O], 180 (5)

[M⁺À HF], 161 (2), 139 (5), 125 (8), 111 (13), 98 (16), 88

(100), 81 (23), 67 (28), 55 (30), 41 (39).

3

¹⁹F NMR (CDCl₃): d À121.8 (dt, J_H,F= 34.3 Hz, J_H,F

=

17.2 Hz). GC/MS (70 eV): m/z (%) 175 (2) [M + H⁺], 174 (9)

[M⁺], 156 (3) [M⁺À H₂O], 154 (0) [M⁺À HF], 139 (0.5)

[154 À CH₃], 123 (30) [154 À CH₂OH], 113 (10) [C₈H₁₇⁺],

4.4.5. 1-Fluoro-1-octyloxirane (5)

99 (15) [C₇H₁₅⁺], 85 (14) [M⁺À C₄H₆OF], 84 (14) [C₆H₁₂

+

A solution of 2-ﬂuorodec-1-ene (3b) (5.64 g, 30.3 mmol

3b, containing 15% dec-1-yne) in CH₂Cl₂(100 mL) was

stirred with meta-chloroperbenzoic acid (7.80 g, 29.8 mmol,

75% purity) at room temperature for 48 h, while the clear

solution became muddy and meta-chlorobenzoic acid

precipitated as a white solid. After ﬁltration the colorless

solution was extracted with a 0.1N Na₂S₂O₃-solution

(50 mL) and a sat. NaHCO₃solution (50 mL). After drying

over MgSO₄and evaporation of the solvent, the residue was

distilled over a Vigreux column at 1.2–1.5 mbar. A fraction

distilling between 45 and 65 8C was collected and analysed.

Yield: 4.38 g (66% of compound 5, 17% of starting material

3b and 17% of dec-1-yne). ¹H NMR (CDCl₃): d 0.88 (t, ³J_H,H

(McLafferty)], 81 (46), 70 (47) [C₄H₆O⁺], 69 (67) [C₅H₉],

+

57 (53) [C₄H₉], 56 (69), 55 (68) [C₄H₇], 43 (100) [C₃H₇],

+

41 (84) [C₃H₅].

4.5. General procedure for the synthesis of acetates and

chloroacetates (method A)

The corresponding allylic alcohol 4 (5 mmol) was

dissolved in dry CH₂Cl₂(5 mL) and treated with pyridine

(0.44 g, 5.57 mmol). Then acetic anhydride (0.58 g,

5.5 mmol) or solid chloroacetic anhydride (0.94 g, 5.5 mmol)

was dissolved under stirring and a catalytic amount of DMAP

was added. After stirring overnight at room temperature the

reaction mixture was dissolved in diethyl ether (30 mL) and

washed with 2N aq. HCl (15 mL), a 5% NaHCO₃-solution

(20 mL) and brine. The organic layer was dried over MgSO₄

and the solvent was removed. The product was puriﬁed by

column chromatography.

= 6.9 Hz, 3 H, 10-CH₃), 1.28 (m, 10 H, 5-CH₂–9-CH₂), 1.52

2

(m, 2 H, 4-CH₂), 1.97 (m, 2 H, 3-CH₂), 2.66 (dd, J_H,H

=

3

2

4.3 Hz, J_H,F= 1.2 Hz, 1 H, 1-CH₂), 3.06 (dddd, J_H,H

4.3 Hz, ³J_H,F= 1.2 Hz, ⁴J_H,H= 1.7 Hz, ⁴J_H,H= 0.5 Hz, 1 H,

1-CH₂). ¹³C NMR (CDCl₃): d 14.0 (q, C-10), 22.6 (t, C-4),

23.5 (t, C-9), 29.1, 29.2, 29.3 (t, C-5–C-7), 31.8 (t, C-8), 31.8

2

(dt, J_C,F= 30.5 Hz, C-3), 50.8 (dt, J_C,F= 22.9 Hz, C-1),

95.2 (d, ¹J_C,F= 261.9 Hz, C-2). ¹⁹F NMR (CDCl₃): d À134.8

(ps t, ³J_H,F= 15.3 Hz). GC/MS (70 eV): m/z (%) 174 (0.07)

[M⁺], 145 (6) [M⁺À C₂H₅], 131 (10) [M⁺À C₃H₇], 123 (15),

103 (13) [M⁺À C₅H₁₁], 98 (20) [C₇H₁₄⁺], 89 (100) [M⁺À

4.5.1. 3-Acetoxy-2-ﬂuorodec-1-ene (9b)

According to the general procedure 2-ﬂuorohex-1-en-3-

ol (4b) (174 mg, 1.0 mmol) was acetylated to give the ester

9b. Yield: 210 mg (91%). ¹H NMR (CDCl₃): d 0.88 (t, ³J_H,H

= 6.9 Hz, 3 H, 10-CH₃), 1.21–1.39 (m, 10 H, 5-CH₂–9-CH₂),

1.72 (m, 2 H, 4-CH₂), 2.08 (s, 3 H, 12-CH₃), 4.53 (dd, ²J_H,H

C₆H₁₃], 81 (29), 76 (50) [C₃H₅OF⁺], 55 (67) [C₄H₇], 43

+

(47) [C₃H₇], 41 (75) [C₃H₅].

+

3

2

= 3.1 Hz, J_H,F= 48.6 Hz, 1 H, 1-CH₂), 4.70 (dd, J_H,H

3

=

3

4.4.6. 2-Fluorodec-2-en-1-ol (6)

3.1 Hz, J_H,F= 16.7 Hz, 1 H, 1-CH₂), 5.28 (dt, J_H,H

3

In a dried Schlenk vessel the crude epoxide prepared

above (4.38 g, containing 22.5 mmol of 5) was dissolved in

CH₂Cl₂(10 mL) under argon. To this solution under stirring

trimethylsilyl triﬂate (TMSOTf) (5.55 g, 25.0 mmol) in dry

CH₂Cl₂(20 mL) was dropped at 0 8C within 10 min. Then

triethylamine (2.53 g, 25.0 mmol) was dropped to the red

brown mixture at the same temperature within 30 min. The

6.9 Hz, J_H,F= 16.2 Hz, 1 H, 3-CH). ¹³C NMR (CDCl₃): d

13.9 (q, C-10), 20.8 (q, C-12), 22.5 (t, C-9), 24.9 (t, C-5),

29.0 (t, C-4), 29.1 (t, C-7), 31.0 (t, C-6), 31.7 (t, C-8), 71.3

2

(dd, J_C,F= 30.5 Hz, C-3), 92.4 (dt, J_C,F= 28.7 Hz, C-1),

1

163.0 (d, J_C,F= 261.9 Hz, C-2), 169.8 Hz (s, C-11). ¹⁹F

3

NMR (CDCl₃): d À111.5 (ddd, J_H,F= 47.7 Hz, J_H,F

=

17.2 Hz, ³J_H,F= 15.2 Hz). GC/MS (70 eV): m/z (%) 216 (0)

F. Tranel, G. Haufe / Journal of Fluorine Chemistry 125 (2004) 1593–1608

1601

[M⁺], 174 (7) [M⁺+ H À CH₃CO], 156 (1) [M⁺

À

(dt, ³J_C,F= 3.8 Hz, C-4), 30.9 (t, C-6), 31.9 (t, C-14), 40.7 (t,

2

C-18), 73.4 (dd, J_C,F= 30.5 Hz, C-3), 93.4 (dd, J_C,F=

2

CH₃COOH (McLafferty)], 141 (1) [156 À CH₃], 127 (6),

118 (2) [C₅H₇O₂F⁺(McLafferty)], 113 (3), 99 (4) [156 À

17.8 Hz, C-1), 161.8 (d, ¹J_C,F= 260.7 Hz, C-2), 166.3 (s, C-

17). ¹⁹F NMR (CDCl₃): d À112.0 (d ps t, J_H,F= 17.2 Hz,

+

C₄H₉], 69 (5) [C₅H₉], 57 (8) [C₄H₉], 55 (15) [C₄H₇], 43

+

3

³J_H,F= 47.7 Hz). GC/MS (70 eV): m/z (%) 334 (0.1) [M⁺],

317 (0.2) [M⁺À OH], 314 (0.3) [M⁺À HF], 299 (5) [M⁺À

Cl], 285 (3) [M⁺À CH₂Cl], 258 (22) [M⁺+ H À

CH₂ClCOO], 240 (5) [M⁺À HO₂CH₂Cl], 211 (23), 180 (8),

152 (17) [M⁺+ H À C₁₃H₂₇], 95 (47), 86 (100), 70 (65), 57

+

(100) [CH₃CO], 41 (21) [C₃H₅].

4.5.2. 3-Chloroacetoxy-2-ﬂuorohex-1-ene (10a)

According to the general procedure the 2-ﬂuorohex-1-en-

3-ol (4a) (590 mg, 5.0 mmol) was esteriﬁed. Yield: 770 mg

(79%). ¹H NMR (CDCl₃): d 0.95 (t, ³J_H,H= 7.4 Hz, 3 H, 6-

CH₃), 1.39 (m, 2 H, 5-CH₂), 1.77 (m, 2 H, 4-CH₂), 4.08 (s, 2

H, 8-CH₂), 4.61 (dd, ²J_H,H= 3.3 Hz, ³J_H,F= 47.9 Hz, 1 H, 1-

CH₂), 4.77 (dd, ²J_H,H= 3.3 Hz, ³J_H,F= 16.5 Hz, 1 H, 1-CH₂),

+

(83) [C₄H₉], 55 (84) [C₄H₇], 43 (100) [C₃H₇].

4.5.5. 3-Chloroacetoxy-2-ﬂuoropropene (10d)

According to the general procedure 2-ﬂuoroprop-2-enol

(4d) (760 mg, 10.0 mmol) was esteriﬁed to give 6d. Yield:

1.28 g (84%). ¹H NMR (CDCl₃): d 4.12 (s, 2 H, 5-CH₂Cl),

4.68 (dd, ²J_H,H= 3.3 Hz, ³J_H,F= 46.7 Hz, 1 H, 3-CH₂), 4.71

3

5.36 (dt, J_H,H= 6.9 Hz, J_H,F= 16.5 Hz, 1 H, 3-CH). ¹³C

NMR (CDCl₃): d 13.5 (q, C-6), 18.1 (t, C-5), 32.9 (t, C-4),

40.7 (t, C-8), 73.1 (dd, ²J_C,F= 28.0 Hz, C-3), 93.5 (dt, ²J_C,F

=

17.8 Hz, C-1), 161.8 (d, ¹J_C,F= 261.9 Hz, C-2), 166.4 (s, C-

7). ¹⁹F NMR (CDCl₃): d À112.1 (ps dt, ³J_H,F= 16.2 Hz, ³J_H,F

= 47.7 Hz). GC/MS (70 eV): m/z (%) 195 (1) [M⁺+ H], 179

(1) [M⁺À CH₃], 167/165 (2/9) [M⁺À C₂H₅], 154/152 (6/15)

[M⁺À C₃H₆], 118 (46) [C₆H₁₁OF⁺(McLafferty)], 100 (100)

[118 À H₂O], 85 (55) [100 À CH₃], 79/77 (28/100)

[C₂H₂OCl⁺], 72 (16), 59 (18), 51/49 (6/21) [CH₂Cl⁺], 41

(d, J_H,F= 14.7 Hz, 2 H, 1-CH₂), 4.86 (dd, J_H,H= 3.3 Hz,

³J_H,F= 15.5 Hz, 1 H, 3-CH₂). ¹³C NMR (CDCl₃): d 40.4 (t,

3

2

C-5), 62.6 (dt, J_C,F= 33.1 Hz, C-1), 95.2 (dt, J_C,F

=

16.5 Hz, C-3), 159.3 (d, ¹J_C,F= 258.1 Hz, C-2), 166.6 (s, C-

4). ¹⁹F NMR (CDCl₃): d À106.1 (ddt, ³J_H,F= 15.3 Hz, ³J_H,F

= 15.3 Hz, ³J_H,F= 47.7 Hz). GC/MS (70 eV): m/z (%) 154/

152 (0.5/1) [M⁺], 134/132 (0/1) [M⁺À HF], 117 (1) [132 À

CH₃], 97 (2), 76 (94) [C₃H₄OF⁺], 59 (100) [C₃H₄F⁺], 51/49

(16/49) [CH₂Cl⁺], 42 (27).

+

(19) [C₃H₅].

4.5.3. 3-Chloroacetoxy-2-ﬂuorodec-1-ene (10b)

According to the general procedure the 2-ﬂuorodec-1-en-

3-ol (4b) (870 mg, 5.0 mmol) was esteriﬁed to give 10b.

=

6.9 Hz, 3 H, 10-CH₃), 1.28 (m, 10 H, 5-CH₂–9-CH₂), 1.77

4.5.6. 1-Chloroacetoxy-2-ﬂuorodec-2-ene (12)

According to the general procedure the ﬂuoroallylic

alcohol 6 (174 mg, 1.0 mmol) was esteriﬁed. Yield: 248 mg

(99%). ¹H NMR (CDCl₃): d 0.88 (t, ³J_H,H= 6.7 Hz, 3 H, 10-

CH₃), 1.28 (m, 10 H, 5-CH₂–9-CH₂), 2.12 (m, 2 H, 4-CH₂),

4.09 (s, 2 H, 12-CH₂), 4.67 (d, ³J_H,F= 17.9 Hz, 2 H, 1-CH₂),

1

Yield: 1.14 g (92%). H NMR (CDCl₃): d 0.88 (t, J_H,H

3

2

(m, 2 H, 4-CH₂), 4.07 (s, 2 H, 12-CH₂), 4.60 (dd, J_H,H

=

3

3.3 Hz, J_H,F= 47.9 Hz, 1 H, 1-CH₂), 4.76 (dd, J_H,H

2

3

3.3 Hz, J_H,F= 16.5 Hz, 1 H, 1-CH₂), 5.34 (dt, J_H,H

3

4.98 (dt, J_H,H= 7.6 Hz, J_H,F= 35.3 Hz, 1 H, 3-CH). ¹³C

NMR (CDCl₃): d 14.0 (q, C-10), 22.6 (t, C-9), 23.6 (dt, ³J_C,F

= 3.8 Hz, C-4), 28.8, 29.0, 29.0 (t, C-5–C-7), 31.7 (t, C-8),

3

6.9 Hz, J_H,F= 16.5 Hz, 1 H, 3-CH). ¹³C NMR (CDCl₃): d

3

14.0 (q, C-10), 22.5 (t, C-9), 24.8 (t, C-5), 29.0 (dt, J_C,F

=

5.1 Hz, C-4), 29.2 (t, C-7), 30.8 (t, C-6), 31.6 (t, C-8), 40.7 (t,

2

40.6 (t, C-12), 63.8 (dt, J_C,F= 31.8 Hz, C-1), 113.0 (dd,

2

C-12), 73.4 (dd, J_C,F= 30.5 Hz, C-3), 93.4 (dt, J_C,F

2

=

²J_C,F= 12.7 Hz, C-3), 152.6 (d, ¹J_C,F= 253.0 Hz, C-2), 166.8

(s, C-11). ¹⁹F NMR (CDCl₃): d À119.8 (dt, ³J_H,F= 19.1 Hz,

³J_H,F= 36.2 Hz). GC/MS (70 eV): m/z (%) 252/250 (0/0)

[M⁺], 216 (1) [M⁺+ H À Cl], 215 (4) [M⁺À Cl], 201 (3) [M⁺

À CH₂Cl], 174 (4) [M⁺+ H À C₂H₂O₂Cl], 167/165 (62/57)

[M⁺À C₆H₁₃], 156 (5) [M⁺À C₂H₃O₂Cl], 136 (2) [156 À

HF], 127 (9), 113 (13) [C₈H₁₇⁺], 99 (23) [C₇H₁₃⁺], 96 (24),

86 (35) [M⁺À C₄H₄O₂FCl], 77 (56) [C₂H₂OCl], 72 (46), 57

17.8 Hz, C-1), 161.8 (d, ¹J_C,F= 259.5, C-2), 166.3 (s, C-11).

¹⁹F NMR (CDCl₃): d À112.1 (ps dt, ³J_H,H= 15.3 Hz, ³J_H,H

=

49.6 Hz). GC/MS (70 eV): m/z (%) 250 (0) [M⁺], 215 (4)

[M⁺À Cl], 201 (5) [M⁺À CH₂Cl], 174 (57) [M⁺+ H À

C₂H₂OCl], 152 (24) [M⁺+ H À C₇H₁₅], 127 (31), 113 (27)

[127 À CH₂], 99 (41) [127 À C₂H₄], 86 (54), 77 (100)

[C₂H₂OCl⁺], 57 (33) [C₄H₉], 55 (51) [C₄H₇], 43 (57)

+

[C₃H₇], 41 (35) [C₃H₅].

+

(21) [C₄H₉], 56 (441), 55 (51) [C₄H₇], 43 (100) [C₃H₇],

+

41 (54) [C₃H₅].

4.5.4. 3-Chloroacetoxy-2-ﬂuorohexadec-1-ene (10c)

According to the general procedure 2-ﬂuorohexadec-1-

en-3-ol (4c) (1.032 g, 4.0 mmol) was esteriﬁed. Yield:

1.26 g (95%). ¹H NMR (CDCl₃): d 0.88 (t, ³J_H,H= 6.4 Hz, 3

H, 16-CH₃), 1.31 (m, 22 H, 5-CH₂–15-CH₂), 1.77 (m, 2 H, 4-

4.5.7. (Z)-3-Chloroacetoxy-2-ﬂuorocyclododecene (23)

According to the general procedure the ﬂuoroallylic

alcohol 22 (400 mg, 2.0 mmol) was esteriﬁed to give the

ester (Z)-23 after chromatography (silica gel, cyclohexane/

ethyl acetate, 40:1). Yield: 0.35 g (63%). ¹H NMR (CDCl₃):

d 1.17–1.69 (m, 14 H, 5-CH₂–11-CH₂), 1.73–1.90 (m, 2 H,

4-CH₂), 1.93–2.07 (m, 1 H, 12-CH₂), 2.33–2.48 (m, 1 H, 12-

CH₂), 4.05 (s, 2 H, 14-CH₂), 5.01 (ddd, ³J_H,H= 5.7 Hz, ³J_H,H

CH₂), 4.07 (s, 2 H, 18-CH₂), 4.60 (dd, ²J_H,H= 3.2 Hz, ³J_H,F

=

2

47.9 Hz, 1 H, 1-CH₂), 4.76 (dd, J_H,H= 3.2 Hz, J_H,F

3

16.5 Hz, 1 H, 1-CH₂), 5.33 (dt, J_H,H= 6.9 Hz, J_H,F

3

16.5 Hz, 1 H, 3-CH). ¹³C NMR (CDCl₃): d 14.0 (q, C-16),

22.6 (t, C-15), 24.8 (t, C-5), 29.1–29.6 (t, C-7–C-13), 29.6

3

= 10.3 Hz, J_H,F= 36.2 Hz, 1 H, 3-CH), 5.28 (ddd, J_H,H

=

1602

F. Tranel, G. Haufe / Journal of Fluorine Chemistry 125 (2004) 1593–1608

3

5.2 Hz, J_H,H= 10.0 Hz, J_H,F= 23.8 Hz, 1 H, 1-CH). ¹³C

(dd, ²J_H,H= 3.1 Hz, ³J_H,F= 16.7 Hz, 1 H, 1-CH₂), 5.28 (dt,

3

NMR (CDCl₃): d 22.7 (dt, J_C,F= 3.8 Hz, C-4), 23.1, 24.1,

3

³J_H,H= 6.7 Hz, J_H,F= 16.0 Hz, 1 H, 3-CH). ¹³C NMR

(CDCl₃): d 9.0 (q, C-13), 14.0 (q, C-10), 22.6 (t, C-9), 24.9 (t,

24.3, 24.5, 25.5, 25.7, 26.1, 28.5 (t, C-5–C-12), 40.9 (t, C-

2

14), 75.3 (dd, J_C,F= 29.3 Hz, C-1), 112.9 (dd, J_C,F

14.0 Hz, C-3), 154.0 (d, ¹J_C,F= 255.6 Hz, C-2), 166.3 (s, C-

13). ¹⁹F NMR (CDCl₃): d À128.6 (dd, ³J_H,F= 22.9 Hz, ³J_H,F

= 36.2 Hz).

2

=

C-5), 27.6 (t, C-12), 29.0 (t, C-4), 29.1 (t, C-7), 31.1 (t, C-6),

31.7 (t, C-8), 71.2 (dd, ²J_C,F= 30.5 Hz, C-3), 92.3 (dt, ²J_C,F

=

17.8 Hz, C-1), 162.9 (d, ¹J_C,F= 259.4 Hz, C-2), 173.3 (s, C-

3

11). ¹⁹F NMR (CDCl₃): d À111.5 (ddd, J_H,F= 15.3 Hz,

³J_H,F= 17.2 Hz, ³J_H,F= 49.6 Hz). GC/MS (70 eV): m/z (%)

4.6. General procedure for synthesis of propionates

(method B)

230 (0) [M⁺], 174 (14) [M⁺À C₃H₄O], 156 (2) [M⁺

À

C₃H₆O₂], 145 (4) [M⁺À C₆H₁₃], 127 (6), 113 (3) [C₈H₁₇⁺],

86 (10), 57 (100) [C₃H₅O⁺] and [C₄H₉], 55 (18) [C₄H₇], 43

+

(17) [C₃H₇], 41 (23) [C₃H₅].

+

The corresponding ﬂuorinated allylic alcohol

4

(10 mmol) in CH₂Cl₂(40 mL) under stirring was treated

with dicyclohexylcarbodiimide (DCC) (2.28 g, 11.0 mmol)

and subsequently with propionic acid (814 mg, 11.0 mmol).

Then a catalytic amount of N,N-dimethylaminopyridine

(DMAP) was added and the mixture was stirred at room

temperature overnight. The reaction mixture was treated

with diethyl ether (200 mL), the dicyclohexyl urea was

ﬁltered and the organic layer was washed with water (3 Â

40 mL), 5% aq. acetic acid (3 Â 40 mL) and again with

water (3 Â 40 mL). The organic layer was dried over

MgSO₄, the solvent was removed and the residue was

puriﬁed by distillation or column chromatography.

4.6.3. 2-Fluoro-3-propionoxyhexadec-1-ene (11c)

According to the general procedure 4c (1.032 g,

4.00 mmol) and propionic acid (407 mg 5.5 mmol) were

reacted. The crude product was ﬁltered through a 10 cm

column (silica gel, cyclohexane/ethyl acetate, 10:1) to give

1

11c as a colorless liquid. Yield: 931 mg (74%). H NMR

(CDCl₃): d 0.88 (t, ³J_H,H= 6.9 Hz, 3 H, 16-CH₃), 1.16 (t, ³J_H,H

= 7.6 Hz, 3 H, 19-CH₃), 1.26 (m, 22 H, 5-CH₂–15-CH₂), 1.73

(m, 2 H, 4-CH₂), 2.36 (q, ³J_H,H= 7.6 Hz, 2 H, 18-CH₂), 4.52

(dd, ²J_H,H= 3.1 Hz, ³J_H,F= 48.4 Hz, 1 H, 1-CH₂), 4.70 (dd,

²J_H,H= 3.1 Hz, ³J_H,F= 16.7 Hz, 1 H, 1-CH₂), 5.28 (dt, ³J_H,H

=

6.9 Hz, ³J_H,F= 16.0 Hz, 1 H, 3-CH). ¹³C NMR (CDCl₃): d 9.0

(q, C-19); 14.0 (q, C-16), 22.7 (t, C-15), 24.9 (t, C-5), 27.6 (t,

C-18), 29.2, 29.3, 29.4, 29.5, 29.6, 29.6, 31.5, 31.9 (t, C-4 and

4.6.1. 2-Fluoro-3-propionoxyhexene (11a)

According to the general procedure 4a (590 mg,

5.00 mmol) and propionic acid (407 mg, 5.5. mmol) were

reacted. The crude product was ﬁltered through a 10 cm

column (silica gel, n-pentane) to give 11a as a colorless

C-6–C-14), 71.2 (dd, ²J_C,F= 31.8 Hz, C-3), 92.3 (dd, ²J_C,F

=

17.8 Hz, C-1), 163.0 (d, ¹J_C,F= 260.7 Hz, C-2), 173.3 (s, C-

17). ¹⁹F NMR (CDCl₃): d À111.4 (ddd, ³J_H,F= 17.2 Hz, ³J_H,F

3

1

= 15.3 Hz, J_H,F= 47.7 Hz). GC/MS (70 eV): m/z (%) 314

liquid. Yield: 590 mg (68%). H NMR (CDCl₃): d 0.94 (t,

³J_H,H= 7.4 Hz, 3 H, 6-CH₃), 1.16 (t, ³J_H,H= 7.6 Hz, 3 H, 9-

CH₃), 1.38 (m, 2 H, 5-CH₂), 1.73 (m, 2 H, 4-CH₂), 2.36 (q,

(0.4) [M⁺], 313 (0.4) [M⁺À H], 299 (0.5) [M⁺À CH₃], 285

(14)[M⁺À C₂H₅], 271(0.8)[M⁺À C₃H₇], 258(33)[M⁺+H À

C₃H₅O], 229 (3), 211 (16), 180 (5), 173 (4), [M⁺À C₁₀H₂₁],

146 (15), 109 (11), 86 (44), 57 (100) [C₃H₅O⁺], 43 (41)

³J_H,H= 7.6 Hz, 2 H, 8-CH₂), 4.53 (dd, ²J_H,H= 3.1 Hz, ³J_H,F

=

2

48.4 Hz, 1 H, 1-CH₂), 4.70 (dd, J_H,H= 3.1 Hz, J_H,F

3

+

3

[C₃H₇].

16.7 Hz, 1 H, 1-CH₂), 5.30 (dt, J_H,H= 6.9 Hz, J_H,F

15.7 Hz, 1 H, 3-CH). ¹³C NMR (CDCl₃): d 9.0 (q, C-9), 13.6

(q, C-6), 18.2 (t, C-5), 27.6 (t, C-8), 33.2 (t, C-4), 70.9 (dd,

²J_C,F= 34.3 Hz, C-3), 92.3 (dt, ²J_C,F= 17.8 Hz, C-1), 162.9

4.6.4. 2-Fluoro-3-propionoxypropene (11d)

According to the general procedure 4d (760 mg,

10.0 mmol) and propionic acid (814 mg, 11.0 mmol) were

reacted to give 11d after careful removing of the solvent using

a Vigreux column and bulp-to-bulp distillation of the residue.

1

(d, J_C,F= 260.7 Hz, C-2), 173.3 (s, C-7). ¹⁹F NMR

3

(CDCl₃):d À111.5 (ddd, J_H,F= 15.3 Hz, J_H,F= 17.2 Hz,

³J_H,F= 47.7 Hz). GC/MS (70 eV): m/z (%) 174 (3) [M⁺], 145

(11) [M⁺À C₂H₆], 132 (8), 118 (24) [C₆H₁₁OF⁺

(McLafferty)], 100 (38) [118 À H₂O], 85 (27) [100 À

1

3

Yield: 700 mg (50%). H NMR (CDCl₃): d 1.17 (t, J_H,H

=

7.6 Hz, 3H, 6-CH₃), 2.39(q, ³J_H,H=7.6 Hz, 2 H, 5-CH₂), 4.60

3

2

CH₃], 73 (8) [C₃H₅O₂], 57 (100) [C₃H₅O⁺], 41 (7) [C₃H₇].

+

(d, J_H,F= 14.1 Hz, 2 H, 1-CH₂), 4.61 (dd, J_H,H= 3.3 Hz,

³J_H,F= 47.5 Hz, 1 H, 3-CH₂), 4.79 (dd, ²J_H,H= 3.3 Hz, ³J_H,F

16.9 Hz, 1 H, 3-CH₂). ¹³C NMR (CDCl₃): d 8.9 (q, C-6), 27.3

=

4.6.2. 2-Fluoro-3-propionoxydecene (11b)

2

(t, C-5), 61.1 (dt, J_C,F= 35.6 Hz, C-1), 94.0 (dt, J_C,F

=

According to the general procedure 4b (1.74 g,

10.0 mmol) and propionic acid (814 mg, 11.0 mmol) were

reacted. The crude product was ﬁltered through a 10 cm

column (silica gel, cyclohexane/ethyl acetate, 10:1) to give

17.8 Hz, C-3), 160.5 (d, ¹J_C,F= 256.9 Hz, C-2), 173.6(s, C-4).

3

¹⁹F NMR (CDCl₃): d À105.9 (ddt, J_H,F= 15.3 Hz, J_H,F

=

15.4 Hz, ³J_H,F= 45.8 Hz). GC/MS (70 eV): m/z (%) 132 (1)

[M⁺], 75 (3) (C₃H₄OF⁺], 57 (100) [C₃H₅O⁺], 39 (4).

1

11b as a colorless liquid. Yield: 2.06 g (90%). H NMR

3

(CDCl₃): d 0.89 (t, J_H,H= 6.9 Hz, 3 H, 10-CH₃), 1.15 (t,

³J_H,H= 7.6 Hz, 3 H, 13-CH₃), 1.29 (m, 10 H, 5-CH₂–9-CH₂),

1.73 (m, 2 H, 4-CH₂), 2.35 (q, ³J_H,H= 7.6 Hz, 2 H, 12-CH₂),

4.52 (dd, ²J_H,H= 3.1 Hz, ³J_H,F= 48.4 Hz, 1 H, 1-CH₂), 4.69

4.6.5. (Z)-2-Fluoro-1-propionoxydec-2-ene (13)

According to the general procedure 6 (174 mg,

1.00 mmol) was reacted with propionic acid (82 mg

F. Tranel, G. Haufe / Journal of Fluorine Chemistry 125 (2004) 1593–1608

1603

1.10 mmol). After chromatographic puriﬁcation (10 cm

silica gel, cyclohexane/ethyl acetate, 10:1) the product 13

(m, 4 H, 2-CH₂and 3-CH₂), 3.68 (s, 3 H, 9-CH₃), 4.54 (dt,

3

³J_H,H= 7.4 Hz, J_H,F= 45.3 Hz, 1 H, 5-CH). ¹³C NMR

1

was isolated as a colorless oil. Yield: 216 mg (94%). H

3

(CDCl₃): d 13.4 (q, C-8), 22.5 (t, C-7), 25.4 (dt, J_C,F

=

5.1 Hz, C-6), 27.6 (dt, J_C,F= 29.2 Hz, C-3), 31.2 (t, C-2),

NMR (CDCl₃): d 0.88 (t, ³J_H,H= 6.9 Hz, 3 H, 10-CH₃), 1.15

2

3

(t, J_H,H= 7.6 Hz, 3 H, 13-CH₃), 1.28 (m, 10 H, 5-CH₂–9-

2

51.5 (q, C-9), 105.8 (dd, J_C,F= 15.3 Hz, C-5), 157.7 (d,

CH₂), 2.11 (m, 2 H, 4-CH₂), 2.37 (q, ³J_H,H= 7.6 Hz, 2 H, 12-

¹J_C,F= 251.8 Hz, C-4), 172.8 (s, C-1). ¹⁹F NMR (CDCl₃): d

À112.0 (m). GC/MS (70 eV): m/z (%) 175 (3) [M⁺+ H], 174

(21) [M⁺], 154 (18) [M⁺À HF], 143 (23) [M⁺À CH₃O], 132

(10) [M⁺+ H À C₃H₇], 111 (9), 101 (59) [M⁺À C₃H₅O₂], 97

CH₂), 4.56 (d, ³J_H,F= 17.9 Hz, 2 H, 1-CH₂), 4.91 (dt, ³J_H,H

=

3

7.6 Hz, J_H,F= 35.8 Hz, 1 H, 3-CH). ¹³C NMR (CDCl₃): d

8.9 (q, C-13), 14.0 (q, C-10), 22.6 (t, C-9), 23.5 (dt, ³J_C,F

=

+

4.0 Hz, C-4), 27.4 (t, C-12), 28.9, 29.0, 29.0 (t, C-5–C-7),

31.7 (t, C-8), 62.2 (dt, ²J_C,F= 31.8 Hz, C-1), 111.6 (dd, ²J_C,F

= 14.0 Hz, C-3), 152.7 (d, ¹J_C,F= 253.0 Hz, C-2), 173.8 (s,

(62), 85 (73), 74 (100), [C₃H₆O₂], 59 (31) [C₂H₃O₂], 55

+

(13), 43 (19) [C₃H₇], 41 (14) [C₃H₅].

+

3

C-11). ¹⁹F NMR (CDCl₃): d À119.5 (dt, J_H,F= 19.1 Hz,

4.7.2. Methyl (Z)-4-ﬂuorododec-4-enecarboxylate (7b)

According to the general procedure, from allylic alcohol

4b (174 mg, 1.00 mmol) the ester 7b was formed. Yield:

194 mg (84%). ¹H NMR (CDCl₃): d 0.80 (t, ³J_H,H= 6.6 Hz, 3

H, 12-CH₃), 1.23 (m, 10 H, 7-CH₂–11-CH₂), 1.96 (m, 2 H, 6-

CH₂), 2.40 (m, 4 H, 2-CH₂and 3-CH₂), 3.61 (s, 3 H, 13-

CH₃), 4.46 (dt, ³J_H,H= 7.4 Hz, ³J_H,F= 37.7 Hz, 1 H, 5-CH).

¹³C NMR (CDCl₃): d 13.9 (q, C-12), 22.5 (t, C-11), 23.4 (dt,

³J_C,F= 5.1 Hz, C-6), 27.3 (t, C-2), 29.0, 31.1, 31.8 (t, C-7–C-

10), 29.2 (dt, ²J_C,F= 28.0 Hz, C-3), 51.5 (q, C-13), 106.0 (dd,

²J_C,F= 15.3 Hz, C-5), 157.6 (d, ¹J_C,F= 251.8 Hz, C-4), 172.6

(s, C-1). ¹⁹F NMR (CDCl₃): d À112.1 (m). GC/MS (70 eV):

m/z (%): 230 (10) [M⁺], 211 (4) [M⁺À F], 210 (28) [M⁺À

HF], 199 (3) [M⁺À OCH₃], 178 (20) [210 À CH₄O], 150

(20) [178 À CO], 145 (30), 136 (51) [M⁺À HF À C₃H₆O₂],

³J_H,F= 36.2 Hz). GC/MS (70 eV): m/z (%) 230 (1) [M⁺], 201

(2) [M⁺À C₂H₉], 187 (1) [M⁺À C₃H₇], 174 (6) [M⁺+ H À

C₃H₅O₂], 156 (7) [174 À H₂O], 145 (11), 127 (3), 113 (5)

[C₈H₁₇⁺], 99 (9) [C₇H₁₅⁺], 86 (11), 72 (17), 67 (8), 57 (100)

+

[C₃H₅O], 43 (17) [C₃H₇], 41 (16) [C₃H₅].

4.6.6. (Z)-2-Fluoro-3-propionoxycyclododec-2-ene (24)

According to the general procedure the allylic alcohol 22

(202 mg, 1.00 mmol) was esteriﬁed. After chromatographic

puriﬁcation (silica gel, cyclohexane/ethyl acetate, 10:1) the

ester 24 was isolated as a viscous oil. Yield: 210 mg (82%).

¹H NMR (CDCl₃): d 1.15 (t, ³J_H,H= 7.4 Hz, 15-CH₃), 1.17–

1.69 (m, 14 H, 5-CH₂–11-CH₂), 1.73–1.90 (m, 2 H, 4-CH₂),

1.93–2.07 (m, 1 H, 12-CH₂), 2.33 (q, ³J_H,H= 7.4 Hz, 2 H, 14-

3

CH₂), 2.33–2.48 (m, 1 H, 12-CH₂), 4.95 (ddd, J_H,H

+

=

5.7 Hz, J_H,H= 10.0 Hz, J_H,F= 36.5 Hz, 1 H, 3-CH), 5.23

97 (45) [C₇H₁₅⁺], 85 (53) [C₆H₁₃⁺], 74 (100) [C₃H₆O₂

3

+

(McLafferty)], 59 (21) [CO₂CH₃], 57 (11) [C₄H₉], 55 (22)

+

(ddd, ³J_H,H= 5.2 Hz, ³J_H,H= 9.8 Hz, ³J_H,F= 23.8 Hz, 1 H, 1-

[C₄H₇], 43 (36) [C₃H₇], 41 [C₃H₅].

+

3

CH). ¹³C NMR (CDCl₃): d 9.0 (q, C-15), 22.6 (dt, J_C,F

=

3.8 Hz, C-4), 23.1, 24.2, 24.4, 24.5, 25.5, 25.8, 26.1, 27.7,

4.7.3. Methyl (Z)-4-ﬂuorooctadec-4-enoate (7c)

According to the general procedure, from allylic alcohol

4c (258 mg, 1.00 mmol) the ester 7c was formed as a white

2

28.8 (t, C-5–C-12, C-14), 73.1 (dd, J_C,F= 29.2 Hz, C-1),

111.6 (dd, ²J_C,F= 14.0 Hz, C-3), 155.0 (d, ¹J_C,F= 255.6 Hz,

C-2), 173.4 (s, C-13). ¹⁹F NMR (CDCl₃): d À127.9 (dd, ³J_H,F

1

waxy solid. Yield: 248 mg (81%). m.p. 32 8C. H NMR

3

= 24.8 Hz, J_H,F= 36.2 Hz).

(CDCl₃): d 0.88 (t, ³J_H,H= 6.9 Hz, 3 H, 18-CH₃), 1.26 (m, 22

H, 7-CH₂–17-CH₂), 2.15 (m, 2 H, 6-CH₂), 2.68 (m, 4 H, 2-

3

4.7. General procedure for the Johnson-Claisen

rearrangement

CH₂and 3-CH₂), 3.67 (s, 3 H, 19-CH₃), 4.53 (dt, J_H,F

=

37.7 Hz, ³J_H,H= 7.4 Hz, 1 H, 5-CH). ¹³C NMR (CDCl₃): d

14.0 (q, C-18), 22.7 (t, C-17), 23.5 (dt, ³J_C,F= 5.1 Hz, C-6),

27.5 (dt, ²J_C,F= 29.3 Hz, C-3), 29.1, 29.3, 29.4, 29.6, 29.6,

31.2, 31.9 (t, C-7–C-16 and C-2), 51.5 (q, C-19), 106.1 (dd,

²J_C,F= 15.3 Hz, C-5), 157.6 (d, ¹J_C,F= 253.0 Hz, C-4), 172.7

(s, C-1). ¹⁹F NMR (CDCl₃): d À112.1 (m). GC/MS (70 eV):

m/z (%) 314 (1) [M⁺], 294 (8) [M⁺À HF], 262 (4), 220 (13),

180 (6), 145 (24) [M⁺À C₁₂H₂₅], 132 (21) [M⁺+ H À

C₁₃H₂₇], 97 (34) [C₇H₁₃⁺], 85 (42) [C₆H₁₃⁺], 74 (100)

In a 10 mL round bottom ﬂask a solution of the

corresponding alcohol (1 mmol), trimethyl orthoacetate

(1.47 mL) and one drop of propanoic acid was reﬂuxed in

dry toluene (2 mL) for 5 h. After cooling to room

temperature, the mixture was poured into water (20 mL)

and the aqueous phase was extracted with diethyl ether (3 Â

10 mL). The combined ethereal extract was washed with

brine (10 mL) and dried over MgSO₄. The product was

puriﬁed by column chromatography (silica gel, cyclohex-

ane/ethyl acetate, 20:1).

+

[C₃H₆O₂], 69 (23) [C₅H₁₁⁺], 67 (17) [C₆H₉], 57 (27)

+

[C₄H₉], 55 (25) [C₄H₇], 43 (41) [C₃H₇], 41 (33) [C₃H₅].

Calcd. for C₁₉H₃₅FO₂(314.26): C 72.57, H 11.22. Found: C

72.50, H 11.43.

4.7.1. Methyl (Z)-4-ﬂuoroct-4-enecarboxylate (7a)

According to the general procedure, from allylic alcohol

4a (118 mg, 1.00 mmol), the ester 7a was formed. Yield:

170 mg (96%). ¹H NMR (CDCl₃): d 0.89 (t, ³J_H,H= 7.2 Hz, 3

H, 8-CH₃), 1.35 (m, 2 H, 7-CH₂), 2.03 (m, 2 H, 6-CH₂), 2.48

4.7.4. Ethyl 3-(1-ﬂuoroethenyl)-decanoate (8)

According to the general procedure, the allylic alcohol 6

(174 mg, 1.00 mmol) was reﬂuxed with triethyl orthoacetate

(1 mL) and one drop of propanoic acid for 20 h. After work-

1604

F. Tranel, G. Haufe / Journal of Fluorine Chemistry 125 (2004) 1593–1608

2

48.4 Hz, 1 H, 1-CH₂), 4.57 (dd, J_H,H= 3.1 Hz, J_H,F

3

up the residue was puriﬁed by HPLC using a RP-18 column

and methanol to give the ester 8 as a colorless liquid. Yield:

94 mg (39%). ¹H NMR (CDCl₃): d 0.79 (t, ³J_H,H= 6.7 Hz, 3

H, 12-CH₃), 1.16 (t, ³J_H,H= 7.2 Hz, 3 H, 14-CH₃), 1.18 (m,

=

3

16.7 Hz, 1 H, 1-CH₂), 5.13 (dt, J_H,H= 6.9 Hz, J_H,F

18.1 Hz, 1 H, 3-CH). ¹³C NMR (CDCl₃): d À2.9 (q, C-13),

À1.4 (q, C-13), 14.1 (q, C-10), 22.6 (t, C-9), 25.0 (t, C-5),

26.9 (t, C-12), 29.1 (t, C-7), 29.1 (t, C-6), 31.1 (t, C-4), 31.8

2

3

12 H, 6-CH₂–11-CH₂), 2.28 (dd, J_H,H= 15.5 Hz, J_H,H

=

2

6.9 Hz, 1 H, 2-CH₂), 2.41 (dd, J_H,H= 15.5 Hz, J_H,H

3

2

(t, C-8), 71.0 (ds, J_C,F= 30.5 Hz, C-3), 92.8 (dt, J_C,F=

17.8 Hz, C-1), 162.9 (d, ¹J_C,F= 262.0 Hz, C-2), 171.9 (s, C-

11). ¹⁹F NMR (CDCl₃): d À112.1 (m). GC/MS (70 eV): m/z

(%) 288 (0.2) [M⁺], 273 (0.7) [M⁺À CH₃], 259 (4) [M⁺À

C₂H₅], 246 (18) [M⁺À C₃H₆], 204 (14), 156 (6) [C₁₀H₁₇F⁺

(McLafferty)], 115 (100) [C₅H₁₁OSi⁺], 75 (38) [C₂H₇OSi⁺],

3

7.6 Hz, 1 H, 2-CH₂), 2.61 (m, 1 H, 3-CH), 4.04 (q, J_H,H

2

7.2 Hz, 2 H, 13-CH₂), 4.18 (dd, J_H,H= 2.9 Hz, J_H,F

3

2

3

50.3 Hz, 1 H, 5-CH₂), 4.45 (ddd, J_H,H= 2.9 Hz, J_H,F

16.7 Hz, ⁴J_H,H= 0.5 Hz, 1 H, 5-CH₂). ¹³C NMR (CDCl₃): d

14.0 (q, C-12), 14.2 (q, C-14), 22.6 (t, C-11), 26.8 (t, C-6),

29.1, 29.3 (t, C-7 and C-9), 31.5 (t, C-8), 31.8 (t, C-10), 37.4

(t, C-2), 39.2 (dd, ²J_C,F= 25.4 Hz, C-3), 60.4 (t, C-13), 90.5

73 (77) [C₃H₉Si⁺], 55 (19) [C₄H₇], 43 (38) [C₃H₇].

+

(dt, ²J_C,F= 20.4 Hz, C-5), 167.1 (d, ¹J_C,F= 260.7 Hz, C-4),

4.8.2. (Z)-2-Chloro-4-ﬂuorooct-4-enoic acid (15a)

3

171.8 (s, C-1). ¹⁹F NMR (CDCl₃): d À106.2 (ddd, J_H,F

=

According to general procedure the ester 10a (398 mg,

2.00 mmol) was rearranged. Different from the general

procedure the combined ethereal phase was extracted with

1N NaOH (3 Â 15 mL) and the ethereal phase was trashed.

The basic solution was acidiﬁed with conc. HCl and

extracted with diethyl ether (3 Â 15 mL). The combined

ethereal layer was washed with water (15 mL) and dried

over MgSO₄. After evaporation of the solvent the product

15a was isolated without further puriﬁcation. Yield: 110 mg

(29%). ¹H NMR (CDCl₃): d 0.90 (t, ³J_H,H= 7.4 Hz, 3 H, 8-

CH₃), 1.38 (tq, ³J_H,H= 7.4 Hz, ³J_H,H= 7.2 Hz, 2 H, 7-CH₂),

19.1 Hz, ³J_H,F= 22.9 Hz, ³J_H,F= 51.5 Hz). GC/MS (70 eV):

m/z (%) 244 (0) [M⁺], 224 (1) [M⁺À HF], 216 (0) [M⁺À

C₂H₄(McLafferty)], 201 (1) [216 À CH₃], 195 (2), 181 (2)

[216 À HF À CH₃], 167 (5) [M⁺À HF À C₄H₉], 156 (1)

[C₁₀H₁₇F⁺(McLafferty)], 146 (28) [M⁺À C₇H₁₄], 156 (16)

[156 À HF], 111 (19), 99 (17) [C₇H₁₅⁺], 95 (19), 93 (20), 81

+

(27), 73 (100) [C₃H₅O₂], 57 (29) [C₄H₉], 55 (56) [C₄H₇],

+

43 (61) [C₃H₇], 41 (72) [C₃H₅].

+

4.8. General procedure for the Ireland-Claisen

rearrangement

2

3

2.07 (m, 2 H, 6-CH₂), 2.71 (ddd, J_H,H= 15.0 Hz, J_H,H

2

=

3

7.8 Hz, J_H,F= 22.7 Hz, 1 H, 3-CH₂), 2.96 (ddd, J_H,H

In a dried Schlenk vessel the respective allylic ester

(2.00 mmol) in CH₂Cl₂(4 mL) was treated under argon with

triethylamine (0.60 g, 6.0 mmol) and TMSOTf (0.46 g,

2.4 mmol) and stirred at room temperature for 4 days, while

the solution turned from colorless to dark red-brown. Then

2N HCl (15 mL) was added and the mixture was stirred

vigorously for 4 h. The phases were separated and the

aqueous was extracted with diethyl ether (3 Â 15 mL).

Further work-up was different for the respective products

and will be mentioned below.

15.0 Hz, ³J_H,H= 6.2 Hz, ³J_H,F= 15.0 Hz, 1 H, 3-CH₂), 4.49

(dd, ³J_H,H= 7.8 Hz, ³J_H,H= 6.4 Hz, 1 H, 2-CHCl), 4.72 (dt,

³J_H,H= 7.5 Hz, ³J_H,F= 37.3 Hz, 1 H, 5-CH), 10.50 (br s, 1 H,

COOH). ¹³C NMR (CDCl₃): d 13.5 (q, C-8), 22.4 (t, C-7),

25.6 (dt, ³J_C,F= 3.8 Hz, C-6), 37.9 (dt, ²J_C,F= 28.0 Hz, C-3),

2

53.1 (d, C-2), 110.1 (dd, J_C,F= 14.0 Hz, C-5), 153.3 (d,

¹J_C,F= 251.8 Hz, C-4), 174.7 (s, C-1). ¹⁹F NMR (CDCl₃): d

3

À114.3 (ddd, J_H,H= 17.2 Hz, J_H,F= 22.9 Hz, J_H,F

=

38.1 Hz). GC/MS (70 eV) (TMS-Ester): m/z (%) 267 (1) [M⁺

+ H], 266 (1) [M⁺], 253/251 (5/1) [M⁺À CH₃], 231 (32) [M⁺

À Cl], 215 (31) [M⁺À HCl À CH₃], 187 (6), 173 (12), 168/

166 (12/6) [C₅H₁₁O₂SiCl⁺(McLafferty)], 150 (15), 141 (36)

[M⁺À HCl À (CH₃)₃SiO], 121 (9) [141 À HF], 99 (12), 93

(32), 77 (39), 73 (100) [(CH₃)₃Si⁺], 45 (12).

4.8.1. 3-(Trimethylsilylacetoxy)-2-ﬂuorodecene (14)

According to general procedure for the Ireland-Claisen

rearrangement, the ester 9b (0.43 g, 2.0 mmol) in dry diethyl

ether (4 mL) was stirred with triethylamine (0.61 g,

6.0 mmol) and TMSOTf (0.46 g, 2.4 mmol) at room

temperature for 4 days. The brown mixture was hydrolysed

with water (20 mL) and extracted with diethyl ether (2 Â

20 mL). After washing the combined ethereal phase with

water (20 mL) and drying over MgSO₄, the solvent was

evaporated and the residue was ﬁltered through a silica gel

column (pentane/diethyl ether, 15:1) to get a colorless oil.

Yield: 0.42 g containing 28% of starting material 9b and

72% of 14. This mixture could not be separated. NMR

spectroscopic data of compound 14 were extracted from the

spectra of this mixture. ¹H NMR (CDCl₃): d 0.00 (s, 9 H, 13-

4.8.3. (Z)-2-Chloro-4-ﬂuorododec-4-enoic acid (15b)

According to general procedure the ester 10b (625 mg,

2.50 mmol) was rearranged and the product 15b was isolated

1

as described for compound 15a. Yield: 340 mg (54%). H

NMR (CDCl₃): d 0.88 (t, ³J_H,H= 6.9 Hz, 3 H, 12-CH₃), 1.27

(m, 10 H, 7-CH₂–11-CH₂), 2.07 (m, 2 H, 6-CH₂), 2.71 (m, 1

H, 3-CH₂), 2.97 (m, 2 H, 3-CH₂), 4.49 (dd, ³J_H,H= 7.6 Hz,

³J_H,H= 6.7 Hz, 1 H, 2-CHCl), 4.71 (dt, ³J_H,H= 7.5 Hz, ³J_H,F

= 37.4 Hz, 1 H, 5-CH). ¹³C NMR (CDCl₃): d 14.0 (q, C-12),

22.6 (t, C-11), 23.6 (dt, ³J_C,F= 5.1 Hz, C-6), 29.0, 29.1, 29.5

(t, C-7–C-9), 31.8 (t, C-10), 37.9 (dt, ²J_C,F= 28.0 Hz, C-3),

CH₃), 0.75 (t, ³J_H,H= 6.7 Hz, 3 H, 10-CH₃), 1.14 (m, 10 H,

53.0 (d, C-2), 110.5 (dd, J_C,F= 15.3 Hz, C-5), 153.1 (d,

¹J_C,F= 251.8 Hz, C-4), 174.4 (s, C-1). ¹⁹F NMR (CDCl₃): d

2

5-CH₂–9-CH₂), 1.59 (m, 2 H, 4-CH₂), 1.80 (d, J_H,H

=

2

1.9 Hz, 2 H, 12-CH₂), 4.42 (dd, J_H,H= 3.1 Hz, J_H,F

3

À114.5 (ddd, J_H,F= 15.3 Hz, J_H,F= 22.9 Hz, J_H,F

=

F. Tranel, G. Haufe / Journal of Fluorine Chemistry 125 (2004) 1593–1608

1605

3

38.2 Hz). GC/MS (70 eV) (TMS-Ester): m/z (%) 322 (1)

[M⁺], 307 (4) [M⁺À CH₃], 287 (42) [M⁺À Cl], 271 (17) [M⁺

À HCl À CH₃], 250 (1) [M⁺+ H À TMS], 227 (1), 197 (11),

(CDCl₃): d À114.4 (ddd, J_H,F= 17.2 Hz, J_H,F= 22.9 Hz,

³J_H,F= 38.2 Hz). GC/MS (70 eV) (TMS-Ester): m/z (%) 406

(1) [M⁺], 391 (3) [M⁺À CH₃], 371 (34) [M⁺+ H À Cl], 370 (6)

[M⁺À Cl], 355 (22) [370 À CH₃], 311 (1), 281 (6), 252 (2),

233 (2), 173 (8), 166 (43) [C₅H₁₁O₂Si⁺], 150 (28), 117 (14)

166 (33), 150 (23), 73 (100) [(CH₃)₃Si⁺], 42 (26) [C₃H₇].

+

4.8.3.1. Methyl (Z)-2-chloro-4-ﬂuorododec-4-enoate. (Z)-

2-Chloro-4-ﬂuorododec-4-enoic acid (15b) (250 mg,

1.00 mmol) and methanol (35.2 mg, 1.10 mmol) were

dissolved in pentane (50 mL). DCC (228 mg, 1.1 mmol)

and a catalytic amount of DMAP were added and the

mixture was stirred at room temperature overnight. The

resulting suspension was ﬁltered and the colorless solution

was washed with water (3 Â 20 mL), 5% aqueous acetic acid

(3 Â 20 mL) and again with water (20 mL). The solution

was dried over MgSO₄, the solvent was removed and the

residue was puriﬁed by column chromatography (silica gel,

cyclohexane/ethyl acetate, 20:1) and the ester was isolated

as a colorless liquid. Yield: 228 mg (86%). ¹H NMR

(CDCl₃): d 0.88 (t, ³J_H,H= 6.9 Hz, 3 H, 12-CH₃), 1.27 (m, 10

[COOSiCH₃], 73 (100) [SiCH₃], 57 (22) [C₄H₉], 55 (26)

+

[C₄H₇], 43 (32) [C₃H₇], 41 (23) [C₃H₅].

+

4.8.5. 2-Chloro-4-ﬂuoropent-4-enoic acid (15d)

According to general procedure the ester 10d (152 mg,

1.00 mmol) was rearranged and the product 15d was isolated

without further puriﬁcation. Yield: 130 mg (86%). ¹H NMR

(CDCl₃): d 2.79 (ddd, ²J_H,H= 15.3 Hz, ³J_H,H= 8.1 Hz, ³J_H,F

= 23.1 Hz, 1 H, 3-CH₂), 3.01 (ddd, ²J_H,H= 14.6 Hz, ³J_H,H

=

6.0 Hz, ³J_H,F= 14.6 Hz, 1 H, 3-CH₂), 4.36–4.59 (m, 2 H, 2-

CHCl and 5-CH₂), 4.75 (dd, ²J_H,H= 3.1 Hz, ³J_H,F= 16.7 Hz,

1 H, 5-CH₂), 7.61 (br s, 1 H, COOH). ¹³C NMR (CDCl₃): d

37.6 (dt, ²J_C,F= 29.2 Hz, C-3), 52.6 (d, C-2), 94.1 (dt, ²J_C,F

=

19.1 Hz, C-5), 160.4 (d, ¹J_C,F= 256.9 Hz, C-4), 173.4 (s, C-

1). ¹⁹F NMR (CDCl₃): d À99.2 (m). GC/MS (70 eV) (TMS-

Ester): m/z (%) 226/224 (0.5/1) [M⁺], 211/209 (3/7) [M⁺À

CH₃], 189 (15) [M⁺À Cl], 173 (4) [M⁺À HCl À CH₃], 167

(1), 137 (2), 117 (5) [C₄H₉O₂Si⁺], 99 (7) [M⁺À HCl À

(CH₃)₃SiO], 93 (39), 73 (100) [(CH₃)₃Si⁺], 53 (23).

H, 7-CH₂–11-CH₂), 2.05 (m, 2 H, 6-CH₂), 2.70 (ddd, ²J_H,H

=

15.3 Hz, ³J_H,H= 8.1 Hz, ³J_H,F= 22.7 Hz, 1 H, 3-CH₂), 2.92

(ddd, ²J_H,H= 15.3 Hz, ³J_H,H= 6.7 Hz, ³J_H,F= 15.3 Hz, 1 H,

3

3-CH₂), 3.79 (s, 3 H, 13-CH₃), 4.44 (dd, J_H,H= 6.7 Hz,

³J_H,H= 7.9 Hz, 1 H, 2-CH), 4.68 (dt, ³J_H,H= 7.6 Hz, ³J_H,F

=

37.4 Hz, 1 H, 5-CH). ¹³C NMR (CDCl₃): d 14.0 (q, C-12),

22.6 (t, C-11), 23.6 (dt, ³J_C,F= 3.1 Hz, C-6), 29.0, 29.0, 29.2

(t, C-7–C-9), 31,8 (t, C-10), 51.6 (d, C-2), 53.1 (q, C-13),

110.1 (dd, ²J_C,F= 14.0 Hz, C-5), 153.5 (d, ¹J_C,F= 251.8 Hz,

C-4), 176.0 (s, C-1). ¹⁹F NMR (CDCl₃): d À114.2 (ddd, ³J_H,F

4.8.6. 2-Chloro-3-(1-ﬂuoroethenyl)-decanoic acid (17)

According to the general procedure the ester 12 (250 mg,

1.00 mmol) was rearranged. After chromatography (silica

gel, cyclohexane/ethyl acetate/acetic acid) the 1:1 mixture

of 17 was isolated as a colorless liquid. Yield: 150 mg

(60%). ¹H NMR (CDCl₃): d 0.88 (t, ³J_H,H= 6.9 Hz, 3 H, 12-

CH₃), 1.28 (m, 10 H, 7-CH₂–11-CH₂), 1.35–1.51 and 1.51–

1.68 (m, 2 H, 6-CH₂), 2.82 (m, 1 H, 3-CH), 4.31 and 4.38 (d,

³J_H,H= 8.6 Hz and ³J_H,H= 8.1 Hz, 1 H, 2-CH), 4.43 and 4.45

(dd, ²J_H,H= 3.1 Hz, ³J_H,F= 49.8 Hz and ²J_H,H= 3.1 Hz, ³J_H,F

= 49.8 Hz, 1 H, 5-CH₂), 4.75 and 4.78 (dd, ²J_H,H= 3.1 Hz,

3

= 15.3 Hz, J_H,F= 21.0 Hz, J_H,F= 38.2 Hz). GC/MS

(70 eV): m/z (%) 266/264 (1/2) [M⁺], 229 (93) [M⁺À Cl],

228 (23) [M⁺À HCl], 209 (4) [M⁺À HF À Cl], 208 (4) [M⁺

À HF À HCl], 177 (5), 157 (8) [C₁₀H₁₈F⁺], 131 (40), 110/

108 (28/100) [C₃H₅O₂Cl⁺(McLafferty)], 81 (26), 59 (29)

+

[C₂H₃O₂], 55 (34) [C₄H₇], 43 (56) [C₃H₇], 41 (32)

+

[C₃H₅].

³J_H,F= 17.4 Hz and ddd, J_H,H= 3.1 Hz, J_H,F= 17.6 Hz,

⁴J_H,H= 0.5 Hz, 1 H, 5-CH₂), 9.81 (br s, 1 H, COOH). ¹³C

NMR (CDCl₃): d 14.0 (q, C-12), 22.6, 26.6, 27.0, 27.6, 28.5,

2

3

4.8.4. (Z)-2-Chloro-4-ﬂuorooctadec-4-enoic acid (15c)

According to general procedure the ester 10c (541 mg,

1.61 mmol) was rearranged. The combined ethereal extract

was washed with brine (2 Â 15 mL), dried over MgSO₄, and

the solvent was removed. The crude product was puriﬁed by

HPLC using an RP-18 column and methanol as the solvent.

The carboxylic acid 15c was isolated as a white solid. Yield:

353 mg (66%). m.p. 48 8C. ¹H NMR (CDCl₃): d 0.88 (t, ³J_H,H

= 6.6 Hz, 3 H, 18-CH₃), 1.26 (m, 22 H, 7-CH₂–17-CH₂), 2.08

(dt, ³J_H,H= 6.7 Hz, ³J_H,H= 6.9 Hz, 2 H, 6-CH₂), 2.72 (ddd,

²J_H,H= 15.0 Hz, ³J_H,H= 7.9 Hz, ³J_H,F= 21.9 Hz, 1 H, 3-CH₂),

2.96 (ddd, ²J_H,H= 15.0 Hz, ³J_H,H= 6.2 Hz, ³J_H,F= 21.2 Hz, 1

H, 3-CH₂), 4.47 (dd, ³J_H,H= 6.2 Hz, ³J_H,H= 7.9 Hz, 1 H, 2-

29.0, 29.1, 29.2, 31.7, 31.7 (t, C-6–C-11), 46.8 (dd, ²J_C,F

=

25.4 Hz, C-3), 47.1 (dd, ²J_C,F= 25.4 Hz, C-3), 56.9 (d, C-1),

58.5 (d, C-2), 94.2 (dt, ²J_C,F= 19.1 Hz, C-5), 95.7 (dt, ²J_C,F

=

1

19.1 Hz, C-5), 162.2 (d, J_C,F= 260.5 Hz, C-4), 162.9 (d,

¹J_C,F= 260.7 Hz, C-4), 174.1 (s, C-1), 174.3 (s, C-1). ¹⁹F

3

NMR (CDCl₃): d À107.8 (ddd, J_H,F= 19.1 Hz, J_H,F

=

3

24.8 Hz, J_H,F= 51.5 Hz, 0.5 F), À105.2 (ddd, J_H,F

3

17.2 Hz, J_H,F= 22.9 Hz, J_H,F= 49.6 Hz, 0.5 H). GC/MS

(70 eV) (TMS-Ester): m/z (%) 325/323 (0/1) [M⁺+ H], 324/

322 (0/1) [M⁺], 287 (10) [M⁺À Cl], 265 (3) [M⁺À H À HCl

À HF], 252 (2), 223 (13) [M⁺À C₇H₁₅], 189 (6), 173 (3), 166

(2) [C₅H₁₁O₂SiCl⁺(McLafferty)], 150 (6), 131 (9) [166 À

3

CH), 4.71 (dt, J_H,H=7.6 Hz, J_H,F= 37.2 Hz, 1 H, 5-CH),

9.45 (br s, 1 H, COOH). ¹³C NMR (CDCl₃): d 14.1 (q, C-18),

22.7 (t, C-17), 23.6 (dt, ³J_C,F= 3.8 Hz, C-6), 29.1, 29.1, 29.4,

Cl], 73 (100) [(CH₃)₃Si⁺], 55 (18) [C₄H₇], 41 (17) [C₃H₅].

+

29.6, 29.6, 29.7 (t, C-7–C-15), 31.9 (t, C-16), 38.0 (dt, ²J_C,F

=

4.8.7. (Z)-4-Fluoro-2-methyloct-4-enoic acid (16a)

According to general procedure the ester 11a (348 mg,

2.00 mmol) was rearranged. After work-up as described for

29.2 Hz, C-3), 53.1 (d, C-2), 110.4 (dd, ²J_C,F= 14.0 Hz, C-5),

1

153.2 (d, J_C,F= 251.8 Hz, C-4), 174.3 (s, C-1). ¹⁹F NMR

1606

F. Tranel, G. Haufe / Journal of Fluorine Chemistry 125 (2004) 1593–1608

compound 15a the product 16a was isolated without further

puriﬁcation. Yield: 110 mg (32%). ¹H NMR (CDCl₃): d 0.89

(t, ³J_H,H= 7.2 Hz, 3 H, 8-CH₃), 1.22 (d, ³J_H,H= 6.9 Hz, 3 H,

was isolated as a colorless liquid. Yield: 163 mg (67%). ¹H

NMR (CDCl₃): d 0.88 (t, ³J_H,H= 6.9 Hz, 3 H, 12-CH₃), 1.18

(d, ³J_H,H= 6.9 Hz, 3 H, 13-CH₃), 1.27 (m, 10 H, 7-CH₂–11-

2

9-CH₃), 1.30–1.44 (m, 2 H, 7-CH₂), 2.03 (m, 2 H, 6-CH₂),

3

CH₂), 2.05 (m, 2 H, 6-CH₂), 2.21 (ddd, J_H,H= 14.6 Hz,

3

2.15–2.79 (br m, 3 H, 2-CH and 3-CH₂), 4.57 (dt, J_H,H

=

³J_H,H= 7.6 Hz, J_H,F= 21.7 Hz, 1 H, 3-CH₂), 2.54 (ddd,

7.5 Hz, ³J_H,F= 37.5 Hz, 1 H, 5-CH), 9.75 (br s, 1 H, COOH).

¹³C NMR (CDCl₃): d 13.5 (q, C-8), 16.2 (q, C-9), 22.5 (t, C-

7), 25.5 (dt, ³J_C,F= 4.0 Hz, C-6), 35.8 (dt, ²J_C,F= 28.0 Hz, C-

3), 36.9 (d, C-2), 107.6 (dd, ²J_C,F= 15.3 Hz, C-5), 156.6 (d,

¹J_C,F= 251.8 Hz, C-4), 182.0 (s, C-1). ¹⁹F NMR (CDCl₃): d

²J_H,H= 14.6 Hz, J_H,H= 6.7 Hz, J_H,F= 17.2 Hz, 1 H, 3-

CH₂), 2.71 (m, 1 H, 2-CH), 3.67 (s, 3 H, 14-CH₃), 4.53 (dt,

³J_H,H= 7.4 Hz, ³J_H,F= 37.7 Hz, 5-CH). ¹³C NMR (CDCl₃): d

3

14.0 (q, C-12), 16.4 (q, C-13), 22.6 (t, C-11), 23.5 (dt, ³J_C,F

=

5.1 Hz, C-6), 29.0, 29.0, 29.4 (t, C-7–C-9), 31.8 (t, C-10),

36.2 (dt, ²J_C,F= 29.2 Hz, C-3), 36.9 (d, C-2), 51.6 (q, C-14),

107.5 (dd, ²J_C,F= 15.3 Hz, C-4), 156.7 (d, ¹J_C,F= 251.8 Hz,

C-5), 176.0 (s, C-1). ¹⁹F NMR (CDCl₃): d À111.8 (ddd, ³J_H,F

3

À111.8 (ddd, J_H,F= 17.2 Hz, J_H,F= 21.0 Hz, J_H,F

=

38.1 Hz). GC/MS (70 eV) (TMS-Ester): m/z (%) 246 (3)

[M⁺], 231 (6) [M⁺À CH₃], 211 (7) [M⁺À HF À CH₃], 203

(1) [M⁺À C₃H₇], 175 (8), 146 (60) [C₆H₁₄O₂Si⁺], 130 (34)

[M⁺+ H À COOTMS], 109 (10) [M⁺À HF À COOTMS], 99

3

= 17.2 Hz, J_H,F= 21.0 Hz, J_H,F= 38.2 Hz). GC/MS

(70 eV): m/z (%) 244 (12) [M⁺], 224 (2) [M⁺À HF], 213 (1)

[M⁺À CH₃O], 209 (4) [224 À CH₃], 175 (2), 159 (9) [M⁺À

C₆H₁₃], 157 (13) [C₁₀H₁₈F⁺], 137 (21) [157 À HF], 111 (29),

+

(22), 73 (100) [(CH₃)₃Si⁺], 56 (24), 41 (13) [C₃H₅].

+

4.8.8. (Z)-4-Fluoro-2-methyldodec-4-enoic acid (16b)

According to general procedure the ester 11b (920 mg,

4.00 mmol) was rearranged. The ethereal solution was

extracted with 1N NaOH (3 Â 30 mL) and the organic layer

was discarded. The basic solution was acidiﬁed with conc.

HCl and extracted with diethyl ether (3 Â 30 mL). The

combined ethereal phase was dried and the solvent was

evaporated. The product 16b was isolated without further

puriﬁcation. Yield: 640 mg (70%). ¹H NMR (CDCl₃): d 0.88

88 (100) [C₄H₈O₂(McLafferty)], 81 (39), 59 (18)

+

[C₂H₃O₂], 57 (15) [C₄H₉], 55 (30) [C₄H₇], 43 (27)

+

[C₃H₇], 41 (28) [C₃H₅]. Calcd. for C₁₂H₂₅O₂F (244.18): C

68.85, H 10.25. Found: C 68.88, H 10.34.

4.8.9. 2-Methyl-4-oxododecanoic acid (27)

According to the above-mentioned procedure the ester

11b (829 mg, 3.60 mmol) was rearranged and the crude

product 16b was subjected to column chromatography under

acidic conditions (silica gel, cyclohexane/ethyl acetate/

acetic acid, 10:1:1) to get 27 as a colorless oil. Yield: 370 mg

(45%). ¹H NMR (CDCl₃): d 0.88 (t, ³J_H,H= 6.6 Hz, 3 H, 12-

CH₃), 1.21 (d, ³J_H,H= 7.2 Hz, 3 H, 13-CH₃), 1.27 (m, 12 H,

6-CH₂–11-CH₂), 1.57 (m, 2 H, 5-CH₂), 2.43 (m, 2 H, 3-

CH₂), 2.95 (m, 1 H, 2-CH). ¹³C NMR (CDCl₃): d 14.0 (q, C-

12), 16.8 (q, C-13), 22.6 (t, C-11), 23.7 (t, C-6), 29.0, 29.1,

29.3 (t, C-7–C-9), 33.5 (d, C-2), 34.5 (t, C-10), 42.9 (t, C-5),

45.4 (t, C-3), 181.5 (s, C-1), 208.9 (s, C-4). GC/MS (70 eV)

(TMS ester): m/z (%) 300 (1) [M⁺], 285 (27) [M⁺-CH₃], 257

(7), 202 (37), 187 (46) [M⁺-C₈H₁₇], 112 (100) [C₈H₁₆⁺], 75

(t, ³J_H,H= 6.9 Hz, 3 H, 12-CH₃), 1.21 (d, ³J_H,H= 6.9 Hz, 3 H,

3

13-CH₃), 1.27 (m, 10 H, 7-CH₂–11-CH₂), 2.05 (dt, J_H,H

=

6.9 Hz, ³J_H,H= 6.7 Hz, 6-CH₂), 2.23 (ddd, ²J_H,H= 14.5 Hz,

³J_H,H= 7.6 Hz, ³J_H,F= 22.2 Hz, 1 H, 3-CH₂), 2.65 (m, 2 H, 2-

CH and 3-CH₂), 4.57 (dt, ³J_H,H= 7.4 Hz, ³J_H,F= 37.7 Hz, 1

H, 5-CH), 11.51 (br s, 1 H, COOH). ¹³C NMR (CDCl₃): d

14.0 (q, C-12), 16.1 (q, C-13), 22.6 (t, C-11), 23.5 (dt, ³J_C,F

5.1 Hz, C-6), 29.1, 29.4 (t, C-7–C-9), 31.8 (t, C-10), 35.8 (dt,

=

2

²J_C,F= 28.0 Hz, C-3), 36.9 (d, C-2), 107.9 (dd, J_C,F

=

15.3 Hz, C-5), 156.4 (d, ¹J_C,F= 251.8 Hz, C-4), 182.3 (s, C-

1). ¹⁹F NMR (CDCl₃): d À112.2 (ddd, ³J_H,F= 15.3 Hz, ³J_H,F

3

= 21.0 Hz, J_H,F= 38.1 Hz). GC/MS (70 eV): m/z (%) 230

+

(47) [C₂H₇OSi⁺], 73 (100) [C₃H₉Si⁺], 57 (31) [C₄H₉], 55

(12) [M⁺], 210 (5) [M⁺À HF], 157 [C₁₀H₁₈F⁺], 137 (38)

(14) [C₄H₇], 43 (26) [C₃H₇], 41 (21) [C₃H₅].

+

[157 À HF], 125 (24) [C₉H₁₇⁺], 97 (10) [C₇H₁₃⁺], 95 (41), 81

+

(49), 74 (62) [C₃H₆O⁺], 55 (100) [C₄H₇], 43 (53) [C₃H₇],

4.8.10. (Z)-4-Fluoro-2-methyloctadec-4-enoic acid (16c)

According to general procedure the ester 11c (314 mg,

1.00 mmol) was rearranged. The combined ethereal extract

was washed with brine (2 Â 15 mL), dried over MgSO₄, and

the solvent was removed. The crude product was puriﬁed by

HPLC using an RP-18 column and methanol as the solvent.

The carboxylic acid 16c was isolated as a white solid. Yield:

+

41 (51) [C₃H₅]. Calcd. for C₁₃H₂₃FO₂(230.17): C 67.79, H

10.07; Found: C 67.63, H 10.41.

4.8.8.1. Methyl (Z)-4-ﬂuoro-2-methyldodec-4-enoate. (Z)-

4-Fluoro-2-methyldodec-4-enoic acid (16b) (230 mg,

1.00 mmol) and methanol (35 mg, 1.10 mmol) were

dissolved in pentane (50 mL). DCC (228 mg, 1.1 mmol)

and a catalytic amount of DMAP were added and the

mixture was stirred at room temperature overnight. The

resulting suspension was ﬁltered and the colorless solution

was washed with water (3 Â 20 mL), 5% aqueous acetic

acid (3 Â 20 mL) and again with water (20 mL). The

solution was dried over MgSO₄, the solvent was removed

and the residue was puriﬁed by column chromatography

(silica gel, cyclohexane/ethyl acetate, 20:1) and the ester

1

225 mg (72%). m.p. 33 8C. H NMR (CDCl₃): d 0.88 (t,

³J_H,H= 6.7 Hz, 3 H, 18-CH₃), 1.22 (d, ³J_H,H= 6.9 Hz, 3 H,

19-CH₃), 1.26 (m, 22 H, 7-CH₂–17-CH₂), 2.04 (m, 2 H,

3

2

3-CH), 2.22 (ddd, J_H,H= 7.6 Hz, J_H,H= 14.6 Hz, J_H,F

3

=

21.9 Hz, 1 H, 3-CH₂), 2.53–2.80 (m, 2 H, 3-CH₂and 2-CH),

4.55 (dt, J_H,H= 7.4 Hz, J_H,F= 37.4 Hz, 1 H, 5-CH). ¹³C

NMR (CDCl₃): d 14.1 (q, C-18), 16.2 (q, C-19), 22.7 (t, C-

3

17), 23.5 (dt, J_C,F= 3.8 Hz, C-6), 29.1, 29.1, 29.3, 29.4,

29.4, 29.6, 29.7 (t, C-7–C-15), 31.9 (t, C-16), 35.8 (dt, ²J_C,F

F. Tranel, G. Haufe / Journal of Fluorine Chemistry 125 (2004) 1593–1608

1607

= 28.0 Hz, C-3), 36.8 (d, C-2), 107.9 (dd, ²J_C,F= 15.3 Hz, C-

5), 156.4 (d, ¹J_C,F= 251.8 Hz, C-4), 181.7 (c, C-1). ¹⁹F NMR

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4.8.11. 4-Fluoro-2-methylpent-4-enoic acid (16d)

According to general procedure the ester 11d (350 mg,

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(5%). H NMR (CDCl₃): d 1.18 (d, ³J_H,H= 6.9 Hz, 3 H, 6-

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3

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4.8.12. 3-(1-Fluoroethenyl)-2-methyldecanoic acid (18)

According to the general procedure the ester 13 (216 mg,

0.94 mmol) was rearranged. The acid 18 was isolated as a

colorless liquid by column chromatography (silica gel,

cyclohexane/ethyl acetate/acetic acid, 10:1:2) as a 81:19

mixture of diastereomers. The isomers could not be

separated by HPLC. Yield: 120 mg (56%); 62% de. ¹H

NMR (CDCl₃): d 0.88 (t, ³J_H,H= 6.9 Hz, 3 H, 12-CH₃), 1.19

(d, ³J_H,H= 7.2 Hz, 3 H, 13-CH₃), 1.27 (m, 10 H, 7-CH₂–11-

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C-11), 41.8 (d, C-2), 45.0 (dd, ²J_C,F= 24.2 Hz, C-3), 91.8 (dt,

²J_C,F= 20.3 Hz, C-5), 166.3 (d, ¹J_C,F= 260.7 Hz, C-4), 181.4

(s, C-1). ¹⁹F NMR (CDCl₃): d À103.2 (ddd, ³J_H,F= 17.2 Hz,

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Acknowledgements

This research project was supported by the Deutsche

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Claisen rearrangements based on vinyl fluorides

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Full text of DOI:10.1016/j.jfluchem.2004.09.001

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