JPS6051462B2 - Method for producing α-thio-γδ-unsaturated carbonyl compound - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is based on the general formula R゜R6 R1 -C-CH=1(I)! 1) COR2R4R5 (wherein R゛ is an alkyl group or aryl group, R2 is an alkyl group, aromatic group, alkoxy group or amino group, R゜,
R', R5 and R° are hydrogen, an alkyl group or an aryl group, and R° and R° or R° and R° can be combined to form an alkylene group.

) The present invention relates to a method for producing an α-thio γ/δ monounsaturated carbonyl compound represented by: More specifically, the present invention provides a compound of the general formula R1SC in the presence of an alkali metal carbonate and/or an alkali metal bicarbonate in an aprotic solvent.
H2C0R2-(■) (wherein, R' and R'' are the same as above.

) and an α-thiocarbonyl compound represented by the general formula R
3-°C=°C-1°C H-X (■) (Used, R3, R4, R5 month, R6ι almost reversed, L-plane 1゛-τ-Xι size halogen.

) The present invention relates to a method for producing an α-thio γ/δ monounsaturated carbonyl compound represented by the general formula (1) by reacting the compound with an allyl compound represented by the formula (1). The group defined as an alkyl group or an aryl group in R3, R4, R5 and R6 in the above general formula may contain a substituent that does not participate in the reaction, and may also contain an unsaturated bond.

The α-thio γ/δ monounsaturated carbonyl compound represented by the general formula (1) that can be produced by the method of the present invention is:
By subjecting this to a reductive desulfurization reaction, it can be converted into a γ/δ monounsaturated carbonyl compound.

Further, by converting the α-thio group in the compound of the general formula (1) into an α-sulfinyl group by oxidation and then subjecting it to a desulfenic acid reaction, a conjugated engineered non-derivative can be produced. These γ/δ monounsaturated carbonyl compounds are known as important intermediates in the synthesis of terpenes, which include a wide range of useful compounds such as fragrances. The present inventors have conducted intensive studies on a method for producing the useful compound represented by the above general formula (1) in an industrially advantageous manner, and as a result, they have developed a process that is easy and safe to operate as described below. The present invention was completed by discovering a method for producing the desired compound.

The method of the present invention uses a compound of the general formula (■) and a compound of the general formula (■).
) in an aprotic solvent in the presence of an alkali metal carbonate and/or an alkali metal hydrogencarbonate.

The embodiment of the reaction is the general formula that is the raw material! The compound of (■) and the compound of general formula (■) are dissolved in approximately equimolar amounts in an aprotic solvent, and an alkali metal carbonate and/or an alkali metal hydrogencarbonate are added to the compound without necessarily maintaining the dissolved state. Always mix and stir. Alkali carbonate used. Approximately equivalent amounts of metal salts or alkali metal hydrogen carbonate salts are sufficient, but there is no problem in using more than that amount. Further, the reaction proceeds smoothly at room temperature without using any special heating or cooling means, but it tends to be accelerated by heating. Examples of apro-tic solvents used as solvents include benzene, methylene chloride, chloroform, acetone, dimethylformamide (DMF), and dimethyl sulfoxide (D
MSO), hexamethyltriamide phosphate (HMPT)
Examples include aprotic solvents well known in the art, such as , tetrahydrofuran, and diethyl ether, but aprotic polar solvents such as DMF and HMPT are particularly preferred. The conventional method for allylating an α-thiocarbonyl compound represented by general formula (■) with an allyl compound represented by general formula (■) is to first allylate a base such as sodium hydride or lithium diisopropylamide under anhydrous conditions. After acting on the compound of general formula (■),
A method of reacting with a compound is known.

However, in this reaction, the compound represented by the general formula (1) cannot be obtained, or the compound represented by the general formula (However, R1, R2, R3
, R4, R5 and R6 are the same as above).

However, if the method of the present invention is used, the compound represented by the general formula (1) instead of the general formula (■) can be produced in good yield without using a base such as sodium hydride or lithium diisopropylamide.

Although the present invention is not intended to be limited by the reaction mechanism theory described below, it is understood that the reaction proceeds as follows.

As is clear from the above reaction formula, in the reaction of the present invention, the α-thiocarbonyl compound does not directly react with the α-carbon substituted by X, but formally involves a nucleophilic attack on the γ-1 position. It can be said that it is specific in that it selectively occurs to give the compound of the general formula (1).

Furthermore, since the method of the present invention uses an alkali metal carbonate and/or an alkali metal hydrogen carbonate in an aprotic solvent, it is easily hydrolyzed into the compounds of general formula (■) and general formula (■), which are raw materials. There is no problem even if the base is included.

Originally, the allyl compound of the general formula (■) is also a compound that is easily hydrolyzed to become an alcohol, but in this method, this reaction is difficult to occur and the desired compound (1) can be efficiently led. As is clear from the above, the present method is capable of producing a compound represented by the general formula (1), in which R2 is an alkoxy group, with a high yield, and the corresponding general formula (■) and general formula (■) It can be said that it is particularly suitable for manufacturing from raw materials.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example 1 667n1 of α-(methylthio)ethyl acetate, 5.0ml of methylene chloride, 1.316y of 1-bromo-2-heptene
and 1.384 f of anhydrous potassium carbonate, and the mixture was heated at room temperature for 15
Stirred for days.

After removing insoluble matter with methylene chloride, it was concentrated under reduced pressure.
The residue was separated by column chromatography (silica gel, benzene and n-hexane) to give 2-methylthio3
503 mg of ethyl-butyl-4-pentenoate was obtained as a pale yellow oil. Yield 43%. Note that this product is 2
It was a mixture of stereoisomers (3:8). Pale yellow liquid Boiling point: 95℃ (oil bath) / 0.15T0rr''.1R (N
eat): 30701295012925, 28501
1470, 1370, 127011 to 17301164
140, 1030, 920dNMR (CDCl3): δ
0.7~1.0(3H,,m), 1.23+1.26(
3H,. t. ．． J=7.4Hz), 1.0~1.6(6
1 (, m), 2.04+2.08 (3H..s), 2.
27-2.64 (1H1m), 3.04 (1H,.d.
．． J=10.0Hz), 3.10+3.16(2H..
q. ．． J=7.4Hz), 3.90~4.12(2HN
m), 4.34-4.75 (1H,.m). Cl2H2
Calculated value as 2O2S: Cl62.56: Hl9.63; Sll3.9
2%. Measured value: Cl62.5O; H19.75:Sll
3.96%. Example 2 α-(methylthio)ethyl acetate 1
．． 1-bromo-2-heptene 2.822 da in 310y,
2.698 g of anhydrous potassium carbonate and 5.0 mL of N●N-dimethylformamide were added, and the mixture was stirred at room temperature for 3 days.

After adding 20 ml of ether and washing with water (3 times with 30 mL), the organic layer was dried over anhydrous sodium carbonate. After concentration under reduced pressure, the reaction mixture was separated by column chromatography (silica gel, benzene and n-hexane), and 2-methylthio3
1.756 da of ethyl-butyl-4-pentenoate was obtained as a colorless oil. Yield 78%. Example 3 Prenyl bromide 1.284 mg in 700 mg α-(methylthio)ethyl acetate
g, 1.443 y of anhydrous potassium carbonate and 2.5 ml of N-N-dimethylformamide were added, and the mixture was stirred at room temperature for 5 days.

After adding 20 ml of ether and washing with water (3 times with 20 ml), the organic layer was dried over anhydrous sodium carbonate. After concentration under reduced pressure, the reaction mixture was separated by column chromatography (silica gel, benzene and n-hexane) to give ethyl 2-methylthio-3,3-dimethyl-4-pentenoate (96%).
2 mg was isolated as a colorless liquid. Yield 91%. IR
(Neat):3075, 2960, 29201286
0, 1740, 172\164011380, 1330N1310 to 137. ．． 1265, 915c71-1 to 11401103. NMR (CDCl3): δ1.18
(6H,.S), 1.25 (3H1t..J=7.2H
z), 2.09 (3H1s), 3.05 (1H1s),
4.13 (2H..qNJ=7.2Hz), 4.96 (
1H1dd. ．． J=11.0, 1.8Hz), 4.98
(1H.sdd.sJ=17.sak1.8Hz), 5.9
5 (1H..ddNJ=17.F!?Sll.OHz)
．． MS (70eV): m/E2O2 (M+, 1.3%)
, 134 (100%, Basepeak), 129 (1
1%), 106 (47%), 88 (36%), 81 (2
1%), 69 (84%), 67 (10%), 61 (15
%), 53 (11%), 41 (67%), 29 (22%
), 27 (15%). In addition, this material was oxidized with hydrogen peroxide (sodium tungstate catalyst in methanol) to lead to a sulfone form.

Colorless liquid boiling point: 130°C (oil bath)/0. 'RTOrr
．． IR (Neat): 3075, 297012925,
1 to 1740, 1730, 1640, 1470, 142
390, 1370, 1320, 1280, 122011
11\1020, 960, 920, 5201410cm
-1. NMR (CDCl3): δ1.30 (3FI..
t. ．． J=7.4Hz), 1.32 (3FI..s),
1.42 (3FI,.s), 3.05 (3H1s), 3
．． 82 (1H..s), 4.28 (2H..q..J=
7.4Hz), 5.17 (1H..d..J=10.8
Hz), 5.19 (1H1d..J=18.0Hz),
6.18 (1H.sdd..J=18.0110.8H
z). Calculated value as ClOHl8O4S: Cl5l. 26: Hl7.74; Sll3.6
8%. Measured value: Cl5l. 34;Hl7.73;Sll
3.64%. Example 4 α-(methylthio)ethyl acetate 6
73m9 was dissolved in 5mL of acetone, 1.418y of 1-bromomethyl-1-cyclohexene and 1.397V of anhydrous potassium carbonate were added, and the mixture was stirred at room temperature for 5 days.

Insoluble matter was removed with methylene chloride, the filtrate was concentrated under reduced pressure, and column chromatography (silica gel, benzene and n-
Hexane) was separated, and 654 mg of ethyl α-methylthio α-(2-methylenecyclohexyl)acetate was added to a pale yellow solution.
Isolated as a colored oil. Yield 57%. Analytical samples were obtained by simple distillation. Colorless oil boiling point: 105°C (oil bath)/0. Liver 0rr'. 1R(Ne
at):3070, 2975, 2925, 285011
730, 165th generation 1450, 129 to 115 to 103
\89h-1. NMR (CDCl3): δ1.30 (3
H,. t,. J=7.4Hz), 1.4~1.9(6H
．． ．． m), 1.9-2.3 (21 (, m), 2.11-2.12 (3H..s), 2.72 (1H..diff
useddd,. J=11.8Hz), 3.42+3.5
4 (1HNd,.J=11.8Hz), 4.23 (2H
．． ．． q. ．． J=7.4Hz), 4.6-4.9 (2H.
m). Calculated value as Cl2H2OO2S: Cl63. l2; Hl8.83; Sll4. O
4%. Measured value: Cl63. l8; Hl8.78; Sll
4. l4%. Example 5 α-(methylthio)ethyl acetate 6
93 mg, 5 ml of acetone, 1.476' (1-bromomethyl-1-cyclohexene) and 1 ml of anhydrous potassium carbonate.
．． 438y was added and stirred at 50°C for 21 hours.

After filtering out insoluble matter with acetone, it was concentrated under reduced pressure, and the residue was separated by column chromatography (silica gel, benzene and n-hexane) to obtain α-methylthio α-(2-
Ethyl (methylenecyclohexyl)acetate 804Tn9 was obtained. Yield tin%. Example 6 651 mg of 1-bromomethyl-1-cyclohexene, 641 ml of anhydrous potassium carbonate and 3 ml of N-N-dimethylformamide were added to 308 mg of ethyl α-(methylthio)acetate, and the mixture was stirred at room temperature for 3 days.

Insoluble materials were filtered off with acetone and concentrated under reduced pressure to obtain crystals. Recrystallization from a small amount of methylene chloride and n-hexane gave 89m9 of pale yellow crystals. Based on NMR, it was estimated to be 1-hydroxymethyl-1-cyclohexene. After concentrating the mother liquor under reduced pressure, it was separated by column chromatography (silica gel, benzene and n-hexane) to isolate 434 m9 of ethyl α-methylthio α-(2-methylenecyclohexyl)acetate as a colorless oil. Yield 83%
. Example 7 To 594 mg of α-(methylthio)ethyl acetate, 783 m9 of 1-bromomethyl-1-cyclohexene, 981 mg anhydrous potassium carbonate, and 2 N-N-dimethylformamide
ml was added and stirred at room temperature for 5 days.

After adding 20 Tnt of ether and washing three times with 20 ml of water, the organic layer was dried over anhydrous sodium sulfate. The reaction mixture obtained by concentration under reduced pressure was separated by column chromatography (silica gel, benzene and n-hexane), and α
-Methylthio alpha-(2-methylenecyclohexyl)ethyl acetate (726 m9) was obtained as a colorless liquid. Yield 72%
. Example 8 1-(Methylthio)undecan-2-one 436M9 was dissolved in 2ml of methylene chloride, and anhydrous potassium carbonate 556M9 was dissolved in 2ml of methylene chloride.
mg and 0.35 mt of crotyl bromide were added, and the mixture was stirred at room temperature for 5 days.

After extraction with methylene chloride (20ml x 4 times), the organic layer was dried over anhydrous sodium carbonate. The reaction mixture obtained by concentration under reduced pressure was separated by column chromatography (silica gel, benzene and n-hexane), and 231 m9 of 3-methyl-4-methylthiol-1-tetradecen-5-one was isolated as a colorless liquid. This was a mixture of two stereoisomers (approximately 1:2). In addition, 212 m9 of raw material 1-(methylthio)undecane-2-one was recovered. Yield 42%. Conversion yield 83%. Colorless liquid boiling point: 140°C (oil bath)/0.0 rr'. 1R(N
eat): 3075, 2950, 2925, 28501
146\910d-1 to 17001164. NMR(C
DCl3): δ0.86 (3H,.t..J=6.0H
z), 0.98+1.12 (3H..d,.J=6.6
Hz), 1.25 (12H,.br.s), 1.3-1
．． 8 (2H,.m), 1.94+1.98 (3H..s
), 2.3-2.8 (3H..m), 2.92 (1H1
d,. J=10.6Hz), 4.84-5.14 (21
(, m), 5.44-5.96 (1H..m). Cl6
Calculated value as H3OOS: Cl7l. O6; Hllll. l7;Sllll.
85%. Measured value: Cl7l. O3; Hllll. 34;S
lll. 70%. Example 9 1-(Methylthio)undecan-2-one 0.36 ml of crotyl bromide in 447Tn9
571 mg of anhydrous potassium carbonate and 5 ml of acetone were added to the mixture, and the mixture was stirred at room temperature for 2 days.

After filtering out insoluble materials with acetone, the mixture was concentrated under reduced pressure. The resulting reaction mixture was separated by column chromatography (silica gel, benzene and n-hexane) to give 3-methyl-4-methylthio-1-tetradecen-5-one 19
2m9 was isolated as a pale yellow liquid. 130 m9 of raw material 1-(methylthio)undecan-2-one was recovered. Yield 34%. Conversion rate is 48%. Example 10 1-(methylthio)undecan-2-one 439Tn9
587 Tng of 1-bromo-2-heptene, 561 TrL9 of anhydrous potassium carbonate, and 5.0 ml of methylene chloride were added to the mixture, stirred at room temperature for 13 days, concentrated under reduced pressure, and the residue was separated by column chromatography (silica gel, benzene and n-hexane). 253 m9 of 3-butyl-4-methylthio 1-tetradecen-5-one was isolated as a pale yellow liquid.

Yield 40%. Pale yellow liquid Boiling point: 170°C (oil bath)/0.
15T'0rrIR (Neat): 2950, 2920
910c1 to 12850, 1705, 16401147
-1. NMR (CDCl3): δ0.86 (6H., b
r. s), 1.26 (18H..br.s), 1.6(
2H. ．． br. m), 1.82 (3H1s), 2.1~
2.7 (3H..m), 3.00 (1H..d., J=
10.6Hz), 4.84-5.14 (211., m)
, 5.35-5.71 (1H,.m). Cl9H36O
Calculated value as S: Cl73. Ol;Hllll. 6l;SllO.
26%.

Measured value: Cl72.85; 65:S,. lO
．． 35%. Example 11 550 WL9 of prenyl bromide, 633 m9 of anhydrous potassium carbonate and 2.0 ml of N●N-dimethylformamide were added to 493 m9 of 1-(methylthio)undecan-2-one, and the mixture was stirred at room temperature for 5 days.

After adding 20 ml of ether and washing with water (3 times with 20 ml), the organic layer was dried over anhydrous sodium sulfate. After concentration under reduced pressure, the resulting reaction mixture was separated by column chromatography (silica gel, benzene and n-hexane), and 3.3
-dimethyl-4-methylthio-1-tetradecene-5-
On 219m9 was isolated as a pale yellow liquid. Yield 34
%. Pale yellow liquid IR (Neat): 2950, 292012850, 1
770, 1710, 1470N138 to 136\9+d
-1. NMR (CDCl3): δ0.6-1.0 (3F
I. ．． m), 1.0-1.4 (16H,.m), 1.4
~1.8 (4H..m), 1.98+2.01C old, s
), 2.2-2.

8 (2H..m), 3.03 (1H1s), 4.95 (
1HNdd. ．． J=10.8, 1.4Hz), 4.96
(1H,.dd,.J=19.8, 1.4Hz),5.
97+6.18 (1H..dd..J=10.&19.
8Hz). MS (70eV): m/E284 (1%, M
218 (5%), 217 (14%), 216 (93
%), 155 (14%), 129 (84%), 129 (
84%), 103 (10%), 95 (10%), 83 (
44%), 82 (11%), 81 (100%), 791
(11%), 71 (18%), 69 (55%), 67 (
16%), 62 (25%), 61 (19%), 57 (2
0%), 55 (21% included 53 (11%), 43 (42%)
), 41 (57%), 29 (19%). Example 12 825 mg of ω-(methylthio)acetophenone was dissolved in 5.0 ml of methylene chloride, 962 m9 of allyl bromide and 1.372 y of anhydrous potassium carbonate were added, and the mixture was stirred at room temperature for 17 days.

After removing insoluble matter with methylene chloride, it was concentrated under reduced pressure.
The resulting reaction mixture was separated by column chromatography (silica gel, benzene and n-hexane) to give 1-phenyl-2-methylthio 4-penten-1-one (380
m9 was isolated as a pale yellow liquid. Yield 37%. In addition,
Raw material ω-(methylthio)acetophenone 262m
9 was recovered, and the conversion yield was 54%. Pale yellow liquid IR (Neat): νCOl6re d-1. NMR (CD
Cl3): δ1.88 (3H..s), 2.34-2.
93 (2H,.m), 4.14 (1H..t,.J=7
．． 4Hz), 4.93-5.27 (2H..m), 5.
81 (1H,.ddd..J=17.0, 10.8, 6
．． 8Hz), 7.26-7.51 (3HNm), 7.8
9-8.01 (211..m). In addition, this product was oxidized with hydrogen peroxide (in methanol, sodium tungstate catalyst) to lead to a sulfone form.

colorless crystal Melting point: 43-45°C. 1R(KBr): νCOl68O, νSO.

l3OOllll3Ocm-1. NMR (CDCl3):
δ2.85-3.03 (2H1m), 2.92 (Tate, s
), 4.81~5.17 (211..m), 5.42~
5.82 (1H..m), 7.34-7.60 (3H..m)
．． m), 7.89-8.04 (211..m). Cl2
Calculated value as Hl4O3S: Cl6O. 48; Hl5.92; Sll3.4
6%. Measured value: Cl6O. 65; Hl5.95; Sll
3.23%. Example 13 1.931 y of allyl bromide, 2.744 g of anhydrous potassium carbonate, and 5.0 ml of N-N-dimethylformamide were added to 1.650 y of ω-(methylthio)acetophenone! The mixture was stirred at room temperature for 3 days.

After adding 20 ml of ether and washing with water (4 times with 30 ml), the organic layer was dried over anhydrous sodium carbonate. After concentration under reduced pressure, the resulting reaction mixture was separated by column chromatography (silica gel, benzene and n-hexane) to obtain 1-
- 1.384y of phenyl-2-methylthio 4-penten-1-one was isolated as a pale yellow liquid. Yield B%.
Example 14 848 m9 of ω-(methylthio)acetophenone was dissolved in 5 ml of methylene chloride, and 1.437 y of 1-bromomethyl-1-cyclohexene and 1.410 y of anhydrous potassium carbonate were dissolved.
was added and stirred at room temperature for 2 days.

Insoluble materials were filtered out with methylene chloride, the filtrate was concentrated under reduced pressure, and separated by column chromatography (silica gel, benzene and n-hexane) to give 795 m of ω-(2-methylcyclohexyl)-ω-(methylthio)acetophenone.
9 was isolated as pale yellow crystals. Yield: 60%. In addition,
195 mg of raw material ω-(methylthio)acetophenone was recovered, and the conversion yield was 78%. Colorless needle crystals (recrystallized from methanol-water (2:1)) Melting point: 81-87C IR (KBr): 166 to 145 to 128 to 89 to 69
h-1. NMR (CDCl3): δ1.2-1.8 (6
H. ．． m), 1.96 (311,.s), 2.1-2.
4(2H,.m), 3.10(1H1diffused
．． ．． d. ．． J=11.6Hz), 4.48(1H..d
1J=11.6Hz), 4.92 (2H..s), 7.
39-7.60 (3H,.m), 7.97-8.12 (
2H. ．． m). Calculated value as Cl6H2OOS: Cl7
3.8O: Hl 7.74: Sll 2.3l%. measured value:
Cl73.67; H17.7O; Sll2.2O%. Example 15ω-(methylthio)acetophenone 893m9
was dissolved in 5 ml of methylene chloride, and 1.402 f of 3-bromo-1-cyclohexene and 1.485 ml of anhydrous potassium carbonate were added.
y was added and stirred at room temperature for 2 days.

After removing insoluble matter with methylene chloride, it was concentrated under reduced pressure.
Column chromatography (silica gel, benzene and n
-hexane) and ω-(2-cyclohexenyl)
580m9 of -ω-(methylthio)acetophenone was isolated as a pale yellow liquid. Yield 44%. Note that 406 mg of raw material ω-(methylthio)acetophenone was recovered, and the conversion yield was 80%. Pale yellow liquid Boiling point: 170℃ (oil bath) / 0.08T'0rT''.1R
(Neat): 291 to 167 α145 to 128 to 69
h-1. NMR (CDCl3): δ1.4-1.9 (4
H. ．． m), 1.8-2.1 (2HNm), 1.87+
1.90 (3H..s), 2.60-3.00 (1H..s)
．． m), 3.85+3.88 (1H,,d..J=11
．． 2Hz), 5.26-6.22 (2H..m), 7.
25-7.55 (31 (, m), 7.84-7.99 (
2H. , m). Calculated value as Cl5Hl8OS: Cl7
3. l3; Hl7.36; Sll3. O2%. measured value:
Cl73. l7; Hl7.37: Sll2.89%. Example 16 α-(methylthio)acetamide 500m9 acetone 5mt11-bromo-2-heptene 1.363
y and 1.314f of anhydrous potassium carbonate and stirred at room temperature.
The mixture was stirred for several days.

After removing insoluble matter with methylene chloride, it was concentrated under reduced pressure and subjected to column chromatography (silica gel, benzene and n-
3-butyl-2-methylthio4
-Pentenamide 604m9 was isolated as colorless crystals. Yield 63%. Note that 67 mg of raw material α-(methylthio)acetamide was recovered, and the conversion yield was 73%. Colorless crystals (purified by silica gel chromatography) Melting point: 69
~70% IR (KBr): 338013170, 295
0, 2920, 2850, 141 to 1665s147 1235d-1. NMR (CDCl3): δ0.7-1
．． 0 (3FI..m), 1.0-1.8 (6H.m),
2.12+2.13(3H..s), 2.3~2.7(
1H. ．． m), 3.17 (1H..d..J=6.6H
z), 4.97-5.20 (211..m), 5.44
~5.90 (1H..m), 6.60 (2H.sbr.
s. ．． (decreased with NH2, D4-MeOH). ClOHl9
Calculated value as ONS: Cl59.66: Hl9.5l:
Nl6.96; Sll5.92%. Measured value: Cl59.
86; Hl9.48; Nl6.92; Sll5.96%
．． Example 17 To 776 mg of ethyl α-(methylthio)acetate, 1.642y1 of 1-bromo-2-heptene, 9
73m9 and NIN-dimethylformamide 2.5
ml was added and stirred at room temperature for 2 days.

After adding 20 ml of ether and washing with water (4 times of 30 ml), the organic layer was dried over anhydrous sodium sulfate. After concentration under reduced pressure, the residue was separated by column chromatography (silica gel, benzene and n-hexane) to obtain 1.028y of ethyl 2-methylthio-3-butyl-4-pentenoate as a colorless oil. Yield 77%. Example 18 To 556 mg of ethyl α-(methylthio)acetate were added 697 m9 of prenyl chloride, 700 m9 of sodium bicarbonate, 100 mg of sodium iodide, and 2.0 ml of N•N-dimethylformamide, and the mixture was stirred at room temperature for 3 days.

Add about 10 mt of ether and wash with water (3 times with 20 m1)
Afterwards, the organic layer was dried with anhydrous sodium sulfate. After concentration under reduced pressure, quantification using column chromatography revealed that 2
-Methylthio It became clear that 669 mg of ethyl 3,3-dimethyl-4-pentenoate was produced. Yield 80%. Example 19 N●N-dimethyl-α-(methylthio)acetamide 1
．． 363y, prenyl bromide 1.723f1 potassium carbonate 2.829q and NIN-dimethylformamide 5.
077! L was added thereto, and the mixture was stirred at room temperature for 3 days.

After filtering off insoluble matter with methylene chloride, the filtrate was concentrated under reduced pressure, separated by column chromatography (silica gel, methylene chloride and ethyl acetate), and N-N-di"methyl-3
- 1.973y of 3-dimethyl-2-methylthio 4-pentenamide was obtained as a pale yellow oil. Yield 96%
. A colorless oil was obtained by distillation and the structure was determined.

．． colorless liquid Melting point: 95-101/4T0rr

Claims (1)

[Claims] 1 In an aprotic solvent, in the presence of an alkali metal carbonate and/or an alkali metal hydrogen carbonate, the general formula R^1SCH
There are general formulas ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ which consists of reacting an α-thiocarbonyl compound represented by _2COR^2 and an allyl compound represented by the general formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ A method for producing an α-thio-γ/δ-unsaturated carbonyl compound represented by R^3, R^4, R^5 and R^6 are hydrogen, an alkyl group or an aryl group, and R^3 and R^5
Alternatively, R^3 and R^6 can be combined to form an alkylene group, and X is a halogen. ]. 2. The method according to claim 1, wherein R^1 is a methyl group.