Syntheses of substituted naphthalenes and naphthols

Journal of the Chinese Chemical Society, 2004, 51, 585-605

585

Syntheses of Substituted Naphthalenes and Naphthols

Keng-Shiang Huang^a,b

(

), Eng-Chi Wang^b* (

) and Hsing-Ming Chen^a,b

(

)

^aGraduate Institute of Pharmaceutical Sciences, Kaohsiung Medical University,

Kaohsiung 807, Taiwan, R.O.C.

^bFaculty of Medicinal and Applied Chemistry, College of Life Sciences, Kaohsiung Medical University,

Kaohsiung 807, Taiwan, R.O.C.

Syntheses of substituted naphthalenes and naphthols are described. Based on Claisen rearrangement,

ring-closing metathesis (RCM), and related reactions, isovanillin was successfully transformed into a series

of substituted naphthalenes and naphthols with good overall yields.

Keywords: Naphthalenes; Naphthols; RCM.

PCy₃

INTRODUCTION

Naphthalenes found in naturally occurring or synthetic

Ph

H

Cl

Grubbs' cat.=

Ru

Pcy₃

compounds often have various biological activities. For ex-

ample, michellamines A-C have anti-HIV activities,¹koru-

pensamines A-D have antimalarial activities,^2,3and (S)-

gossypol has antifertility, anti-HIV, and anti-cancer activi-

ties.⁴Furthermore, 1-naphthol, used as a starting material for

the construction of propranolol,⁵has been widely used in

clinics as beta blocker until today. Apart from their interest-

ing biological activities, biaryl naphthalene or naphthol com-

pounds have also found application as chiral reagents.⁶

(1,1¢-Binaphthyl)-2,2¢-diol and its derivatives, for example,

are widely used in asymmetric synthesis, either as ligands or

as chiral auxiliaries.⁷However, only a few naphthalenes

and naphthols with functional substituents have been de-

scribed.^8-10Major synthetic strategies include the following:

(i) Diels-Alder reaction of o-quinodimethanes with dieno-

philes,^10a(ii) cyclization of 2-allylacetophenone with potas-

sium tert-butoxide,^8f(iii) anionic cyclization of 2-(1-pro-

penyl)benzamides with base,^8fand (iv) intramolecular cy-

clizations of 4-phenylbutyric acid with Lewis acid-

catalysed.^10bHowever, these methods have certain draw-

backs, such as low yields, slow reaction times, and commer-

cial unavailability of starting materials. Thus, the develop-

ment of an efficient method of constructing naphthalenes

with functional substituents is necessary. In 1995, Grubbs, et

al.¹¹discovered a novel ruthenium- benzylidine carbene com-

plex (Grubbs cat.) catalyzed ring closing olefin metathesis

(RCM), which has received a wide and rapid application in

organic synthesis.^12,13Recently we preliminarily reported a

novel method of synthesizing substituted naphthalenes¹⁴

based on this RCM chemistry. The results and full experi-

mental details, in addition to a concise synthesis of substi-

tuted naphthols, are disclosed herein. The synthetic strategy

is based on the following protocol: (i) various allylisovanil-

lins (2a-d) undergo [3,3] sigmatropic (Claisen) rearrange-

ment to give 2-allyl-3-hydroxy-4-methoxybenzaldehydes

(3a-b), and 2-allyl-5-hydroxy- 4-methoxy-benzaldehydes

(4b-d), respectively (Scheme I), followed by O-alkylation

with various alkyl halides to furnish ortho and (or) para-de-

rivatives as key intermediates (5a-f, 6a-c); (ii) subsequently,

the key intermediates are allowed to react with vinyl magne-

sium bromide to give corresponding alcohols (7a-f, 8a-c), re-

spectively; (iii) the resulting alcohols are subjected to RCM

reaction to undergo cyclization together with dehydration

spontaneously in situ to produce various substituted naph-

thalenes (9a-f, 10a-c), respectively (Scheme II); (iv) the re-

sulting alcohols (7a-f, 8a-c) obtained from ii were oxidized

with pyridinium chlorochromate (PCC) or Dess-Martin peri-

odinane (dMP) to afford the corresponding ketones (11a-f,

12a-c), respectively; (v) finally, these ketone derivatives

were treated with Grubbs catalyst to undergo RCM and fur-

nish benzocyclohexenones (13a-f, 14a-c), which were then

tautomerized in situ to give a series of substituted naphthols

(15a-f, 16a-c), respectively (Scheme III). Thus, a practical,

* Corresponding author. E-mail: enchwa@kmu.edu.tw

586 J. Chin. Chem. Soc., Vol. 51, No. 3, 2004

Huang et al.

versatile, and straightforward method for synthesizing these

title compounds was established based on the Claisen rear-

rangement, RCM, and related reactions from isovanillin.

different ratio of ortho and para products. We found a simple

allylisovanillin (2a) was heated in neat, in decalin or in N,N-

diethylaniline to furnish an exclusively ortho product, 2-

allyl-3-hydroxy-4-methoxybenzaldehyde (3a) in 92-95%

yields, and no para product 4a was observed. On the other

hand, when 2b was treated under the same conditions, reac-

tion time was longer; 16 hrs was needed accomplish the reac-

tion, and to give both ortho (3b) and para product (4b) in var-

ious ratios with 3b/4b: 48/36, 71/10, and 67/20. The bulky

allylisovanillin (2c) or (2d), when treated under the same

conditions of Claisen rearrangement for 2a, furnished almost

always para product 4c or 4d. The results of our previous

study, with extended entries, are summarized in Table 1.

The identification of ortho or para products for this

Claisen rearrangement could be easily confirmed by examin-

RESULTS AND DISCUSSION

As a general procedure and in accordance with our pre-

vious report,¹⁴isovanillin (1) was alkylated with various al-

lylic halides such as allyl bromide, 1-bromo-2-butene, trans-

cinnamyl chloride, and 1-bromo-3-methyl-2-butene in anhy-

drous acetone in the presence of potassium carbonate to give

various allylisovanillins (2a-d) in yields of 86-92%, respec-

tively (Scheme I). The Claisen rearrangement of these vari-

ous allylisovanillins (2a-d) was respectively carried out un-

der three different conditions: (A) by heating in neat, (B) on

the reflux in decalin, and (C) in N,N-diethylaniline to give the

1

ing the coupling constants of two aromatic protons in H

NMR spectra. In the case of double doublet split, it belonged

Scheme I

OH

R₁

R₂

CH₃O

R₁

R₂

CHO

OH

O

a. R =R =H

1

2

i

ii

3

CH₃O

b. R

=H, R =CH

2

3

CHO

1

CHO

HO

2

R₂

R₁

a. R =R =H

b. R =H, R =CH

1 2 3

1

2

CH₃O

c. R =H, R =C H

6 5

d. R =R =CH

3

1

2

1

2

4

c. R =H, R =C H

6 5

b. R =H, R =CH

3

1

2

1

2

d. R =R =CH

3

1

2

^aConditions: (i) allyl bromide, or 1-bromo-2-butene, or trans-cinnamyl chloride, or

1-bromo-3-methyl-2-butene, K₂CO₃, Acetone, reflux 8h; (ii) A. heated in neat at

gently boiling 170 ^oC; or B. heated in decalin under the 180 ^oC reflux; or C. heated

in N,N-diethylanilline under the 217 ^oC reflux.

Table 1. Conditions and % Yields of 3a-b, 4b-d after the Claisen Rearrangement of 2a-d

Compounds

Conditions (°C/solvent)

Reaction time (hr)

Products (% yields)

2a

170-180/neat

180/decalin

217/diethylaniline

170-180/neat

180/decalin

217/diethylaniline

170-180/neat

180/decalin

217/diethylaniline

170-180/neat

180/decalin

3

5

1

16

--

12

1

3a (92)

3a (95)

3b (48)

3b (71)

3b (67)

3c (--)

3d (--)

4a (--)

4b (36)

4b (10)

4b (20)

4c (--)

4c (65)

4c (76)

4d (79)

4d (58)

4d (80)

2b

2c

2d

6

217/diethylaniline

Syntheses of Substituted Naphthalenes and Naphthols

J. Chin. Chem. Soc., Vol. 51, No. 3, 2004 587

to ortho product, but if singlet, it belonged to para product in

the structure of 3 or 4. For example, 4c showed two singlet

one-proton signals at 6.76 and 7.43 ppm, indicating the allyl

group located at the para position to the hydroxyl group in

the structure. A broad one-proton signal at 5.79 ppm pre-

sented in the ¹H NMR spectrum of 4c, disappeared after addi-

tion of D₂O, indicating the existence of an OH group. To

gather further evidence to support formation of 4c, high-

resolution mass spectroscopy showed the desired molecular

formula C₁₇H₁₆O₃. The NOESY experiments of 4c revealed

the following correlations: (a) CHO « H-1¢, H-6, H-2¢, H-3¢;

(b) H-3 « OCH₃, H-2¢, H-3¢. The ¹³C NMR spectra showed

15 lines (carbons) were found, which matched the structure

of 4c. The aromatic protons of compounds 3a-b and 4b-d in

¹H NMR spectra are compiled in Table 2.

Synthesis of naphthalenes¹⁴

Subsequently, the products of Claisen rearrangement,

3a, 3b, and 4b were alkylated as a general procedure with

various alkyl halides such as methyl iodide, ethyl iodide, and

benzyl bromide in anhydrous acetone in the presence of po-

tassium carbonate to give 5a-f and 6a-c in yields of 80-98%

(Scheme II). The structures of 5a-f and 6a-c are supported by

their ¹H and ¹³C NMR spectra. The ¹H-NMR spectra exhib-

ited a new methoxy signal at 3.85 ppm in 5a, a new ethoxy

signal at 1.36 ppm (t, J = 7.0 Hz, 3H), and at 3.96 ppm (q, J =

7.0 Hz, 2H) in 5b, and two benzylic protons at 4.99 ppm (s,

2H), and one additional five-aromatic proton at 7.3-7.5 ppm

Table 2. ¹H NMR of Aromatic Protons Presented in 3a-b and 4b-d

R

HO

R

2

6

1

HO

CHO

MeO

'

2

R

2

MeO

5

'

3

CHO

1

6

R

1

3

4

Enrty

R₁

R₂

H

CH₃

C₆H₅

CH₃

Compound 3

Compound 4

H-5

H-6

H-3

H-6

3a

3b

4b

4c

4d

H

CH₃

6.71 (d, J = 8.4 Hz)

6.86 (d, J = 8.5 Hz)

7.27 (d, J = 8.4 Hz)

7.46 (d, J = 8.5 Hz)

6.70 (s)

6.76 (s)

6.71 (s)

7.41 (s)

7.43 (s)

7.40 (s)

Scheme II

OR₃R₁

OH R₁

MeO

ii

iii

MeO

i

CHO

3a, R₁=H

OH

9a-f

7a-f

5a-f

a. R₁=H, R₃=CH₃

b. R₁=H, R₃=C₂H₅c. R₁=H, R₃=CH₂C₆H₅

3b, R₁=CH₃

d. R₁=CH₃, R₃=CH₃e. R₁=CH₃, R₃=C₂H₅f. R₁=CH₃, R₃=CH₂C₆H₅

OH

OR₃

MeO

R₃O

i

ii

iii

OH

CHO

CH₃

MeO

CH₃

8a-c

b. R₃=C₂H₅

4b

6a-c

10a-c

c. R₃=CH₂C₆H₅

a. R₃=CH₃

^aConditions: (i) methyl iodide, or ethyl iodide, or benzyl bromide, K₂CO₃, Acetone, reflux

8h; (ii) vinyl magnesium bromide, THF, 0 ^oC, 2h; (iii) 5 % Grubbs cat., 0.05 M CH₂Cl₂, rt.

588 J. Chin. Chem. Soc., Vol. 51, No. 3, 2004

Huang et al.

in 5c, in comparision with starting materials, 3a-b and 4b.

This was followed by the addition of Grignard reagent (vinyl

magnesium bromide) to compounds 5a-f or 6a-c, which gave

the 1,2-addition product, 1-(2-allyl-3-alkoxy-4-methoxy-

phenyl)-2-propen-1-ols (7a-c), 1-[3-alkoxy-4-methoxy-2-

(1-methylallyl)-phenyl]-2-propen-1-ols (7d-f), and 1-[5-

alkoxy-2-(2-butenyl)-4-methoxyphenyl]-2-propen-1-ols

(8a-c) in good yields, respectively.

higher field (d = 1.81) in 7e. Some characteristic protons and

¹³C-NMR data of compounds 7a-f and 8a-c are summarized

in Table 3.

Finally, by treating these dienes 7a-c and 8a-c with 5%

mole of Grubbs catalyst in 0.05 M anhydrous CH₂Cl₂to un-

dergo RCM, followed by dehydration in situ, a series of

disubstituted naphthalenes (9a-c, 10a-c) were produced in

good yields. If the diastereomeric mixture (7d-f) were treated

with Grubbs catalyst to undergo RCM, the corresponding

trisubstituted naphthalenes (9d-f) were produced. The struc-

tures of naphthalenes 9a-f and 10a-c were assigned by their

¹H, ¹³C, and 2D-NMR. For example, the ¹H-NMR spectrum

of 9a showed signals from the two ortho-coupled protons H-3

and H-4 on the more electron-rich ring at d 7.31 and 7.60 (J =

9.0 Hz), respectively. Signals from two other aromatic pro-

tons H-6 and H-7 appeared as triplets at d 7.36 and 7.48 (J =

7.5 Hz), respectively. Signals from the remaining two aro-

matic protons H-5 and H-8 appeared as doublets at d 7.81 and

8.13 (J = 8.5 Hz), respectively. Finally, the two methoxy

groups generated signals in their characteristic regions of d

4.03 and 4.10. In addition, COSY cross-peaks indicated se-

quences of (a) H-3 to H-4; and (b) H-6 to H-7, H-5 and H-8.

¹³C-NMR spectra showed 12 carbons with the presence of

two methoxy carbons, six sp²tertiary, and four sp²quaternary

carbons. High-resolution mass spectroscopy showed the de-

sired molecular ion at m/z 188.0839 (C₁₂H₁₂O₂requires M,

188.0837). Further structural proof for the naphthalenes sub-

Evidence of the formation of the propen-1-ols 7a-f and

8a-c was confirmed by examining the presence of a new for-

mation of secondary alcohol group or the disappearance of

formyl group in ¹H or ¹³C-NMR spectra, in comparison with

starting materials. For example, the ¹H-NMR spectrum of 8a,

showed the hydroxy signal at d 2.31, and the disappearance of

formyl proton at d 10.19 in comparision with starting mate-

rial 6a, was observed. The ¹³C-NMR spectrum also con-

firmed the assignment, as the characteristic signal for car-

bonyl (d 189.6) carbon of 6a had disappeared. In addition,

high-resolution mass spectroscopy showed the expected mo-

lecular ion of 6a at m/z 248.1412 (C₁₅H₂₀O₃requires M,

248.1412). The addition of vinyl Grignard reagent to com-

pounds 5d-f afforded two diastereomers 7d-f in a ratio of 3:2

which were determined by the integrated values of ¹³C-NMR.

Their structures are depicted in the experimental section to-

gether with some characteristic chemical shifts. Whereas the

OH signal of one of the diastereomers appears at d = 1.90, the

corresponding OH signal of the other isomer is shifted to a

Table 3. Characteristic Spectroscopic Data of the Propen-1-ols (7a-f, 8a-c)

OR₃

R₁

Hb

Ha

OH

MeO

R₃O

1

Hc

Hb

Hc

1

Ha

CH₃

MeO

OH

7

8

Substrate

¹H NMR (CDCl₃)

¹³C

NMR

C-1

Formula

HRMS

calcd

OH

(br s)

Ha

Hb

Hc

found

7a

7b

7c

7d*

7e*

7f*

8a

8b

8c

2.15

2.11

2.09

2.13

1.90

1.98

2.31

2.11

1.84

4.90

4.91

4.79

5.00

5.04

4.99

5.31

5.30

5.27

5.01

4.87

5.05

5.06

5.03

5.18

5.17

5.14

5.31

5.20

5.31

5.33

6.01

6.00

5.94

70.50

70.58

70.76

70.95

70.75

70.70

70.67

70.70

70.67

C₁₄H₁₈O₃

C₁₅H₂₀O₃

C₂₀H₂₂O₃

C₁₅H₂₀O₃

C₁₆H₂₂O₃

C₂₁H₂₄O₃

C₁₅H₂₀O₃

C₁₆H₂₂O₃

C₂₁H₂₄O₃

234.1256

248.1409

310.1569

248.1412

262.1569

324.1725

248.1414

262.1569

324.1725

234.1249

248.1409

310.1562

248.1410

262.1577

324.1720

248.1412

262.1567

324.1726

*The selected data of the major diastereomer.

Syntheses of Substituted Naphthalenes and Naphthols

J. Chin. Chem. Soc., Vol. 51, No. 3, 2004 589

Table 4. The Selected ¹H NMR Spectra of Substituted Naphthalenes (9a-f, 10a-c)

OR₃R₁

8

1

R₃O

7

6

MeO

7

6

3

MeO

5

4

5

4

9a-f

H-3

10a-c

H-1

H-4

H-5

H-6

H-7

H-8

9a

9b

9c

9d

9e

9f

10a

10b

10c

-

7.31(d)

7.03(d)

7.37(d)

7.29(d)

7.21(d)

7.31(d)

-

7.60(d)

7.35(d)

7.68(d)

7.60(d)

7.53(d)

7.62(d)

7.13(s)

7.16(s)

7.81(d)

7.57(d)

7.50(d)

7.23(d)

7.18(d)

7.21(d)

7.70(d)

7.68(d)

7.62(d)

7.36(t)

7.15(t)

7.42(t)

7.62(t)

7.56(t)

7.61(t)

7.35(t)

7.33(t)

7.32(t)

7.48(t)

7.28(t)

7.52(t)

7.22(d)

7.16(d)

7.20(d)

7.35(t)

7.33(t)

8.13(d)

8.02(d)

8.24(d)

-

7.13(s)

7.14(s)

7.70(d)

7.68(d)

-

structure came from the 2D-NMR spectroscopy. The NOESY

experiments of 9a-f and 10a-c exhibited the following corre-

lations: (a) the spectrum of 9a showed OCH₃-2 « H-3,

OCH₃-1; H-4 « H-3, H-5; and H-7 « H-8, H-6; (b) the spec-

trum of 9e showed OCH₃-2 « H-3, OEt-1; H-7 « H-6,

Me-8; and H-5 « H-6, H-4; (c) the remaining spectrum of

10c showed OCH₃-2 « H-1, OCH₂C₆H₅-3; H-8 « H-7, H-1;

and H-5 « H-6, H-4. The selected ¹H-NMR spectral data of

compounds 9a-f and 10a-c are summarized in Table 4.

Furthermore, this transformation was of particular

value because the naphthalenes (9f, 10c) formed crystals

suitable for X-ray analysis. The structure of 9f was firmly

established by a single-crystal X-ray structure identification

as 1-benzyloxy-2-methoxy-8-methylnaphthalene, and the

ORTEP view showed the trisubstituted naphthalene at C-1,

C-2, and C-8 in Fig. 1. The disubstituted naphthalene 10c was

also confirmed by X-ray analysis as 2-benzyloxy-3-meth-

oxy-naphthalene. The ORTEP diagram of 10c is presented in

Fig. 2. Selected bond distances and bond angles for 9f and

10c are given in the experimental section Table 5 and Table 6,

respectively.

Synthesis of naphthols

Oxidation of propen-1-ols 7a-f and 8a-c carried out by

either PCC or dMP (dess Martin periodinane), gave com-

pound 11a-f or 12a-c in 60-69% yields (Scheme III), together

with other undesired byproducts in yields of 28-32%.

The chemical elucidation of vinyl ketone 11a-f and

12a-c could be confirmed by examining the new formation of

Fig. 2. X-ray crystal structure of naphthalene (10c).

Fig. 1. X-ray crystal structure of naphthalene (9f).

590 J. Chin. Chem. Soc., Vol. 51, No. 3, 2004

Huang et al.

Table 5. Selected Crystallographic Bond Distances (Å) for Compounds 9f and 10c

atom-atom

distance

atom-atom

distance

atom-atom

distance

9f^a

O(1)-C(1)

O(2)-C(19)

C(2)-C(3)

C(5)-C(6)

C(7)-C(8)

C(9)-C(10)

C(13)-C(18)

C(16)-C(17)

1.385(5)

1.412(6)

1.403(6)

1.354(7)

1.361(7)

1.436(6)

1.379(7)

1.357(8)

O(1)-C(12)

C(1)-C(2)

C(3)-C(4)

C(5)-C(10)

C(8)-C(9)

C(12)-C(13)

C(14)-C(15)

C(17)-C(18)

1.452(5)

1.379(6)

1.351(7)

1.419(6)

1.434(6)

1.475(6)

1.392(8)

1.407(8)

O(2)-C(2)

C(1)-C(9)

C(4)-C(10)

C(6)-C(7)

C(8)-C(11)

C(13)-C(14)

C(15)-C(16)

1.376(5)

1.418(6)

1.403(7)

1.407(7)

1.516(6)

1.400(7)

1.359(8)

10c^a

O(1)-C(2)

O(2)-C(18)

C(2)-C(3)

C(5)-C(6)

C(7)-C(8)

C(11)-C(12)

C(13)-C(14)

C(16)-C(17)

1.368(2)

1.427(3)

1.429(3)

1.363(3)

1.365(3)

1.501(3)

1.383(3)

1.385(3)

O(1)-C(11)

C(1)-C(2)

C(3)-C(4)

C(5)-C(10)

C(8)-C(9)

C(12)-C(13)

C(14)-C(15)

1.433(3)

1.359(3)

1.411(3)

1.415(3)

1.371(3)

1.365(4)

O(2)-C(3)

C(1)-C(9)

C(4)-C(10)

C(6)-C(7)

C(9)-C(10)

C(12)-C(17)

C(15)-C(16)

1.364(2)

1.414(3)

1.415(3)

1.389(4)

1.407(3)

1.378(3)

1.361(4)

^aAll C-H bond distances are 0.95 Å.

Table 6. Selected Crystallographic Bond Angles (deg) for Compounds 9f and 10c

Atom

angle

atom

angle

atom

angle

9f

C(2)-O(1)-C(11)

O(1)-C(2)-C(1)

O(2)-C(3)-C(2)

C(3)-C(4)-C(10)

C(6)-C(7)-C(8)

C(1)-C(9)-C(10)

C(4)-C(10)-C(9)

C(11)-C(12)-C(13)

C(12)-C(13)-C(14)

C(15)-C(16)-C(17)

116.9(2)

126.0(2)

114.4(2)

121.1(2)

120.1(2)

119.0(2)

119.1(2)

120.7(2)

120.6(2)

120.0(2)

C(3)-O(2)-C(18)

O(1)-C(2)-C(3)

O(2)-C(3)-C(4)

C(6)-C(5)-C(10)

C(7)-C(8)-C(9)

C(8)-C(9)-C(10)

C(5)-C(10)-C(9)

C(11)-C(12)-C(17)

C(13)-C(14)-C(15)

C(12)-C(17)-C(16)

116.9(2)

113.9(2)

126.1(2)

120.6(2)

121.1(2)

118.3(2)

119.2(2)

120.8(2)

120.2(2)

120.7(2)

C(2)-C(1)-C(9)

C(1)-C(2)-C(3)

C(2)-C(3)-C(4)

C(5)-C(6)-C(7)

C(1)-C(9)-C(8)

C(4)-C(10)-C(5)

C(1)-C(11)-C(12)

C(13)-C(12)-C(17)

C(14)-C(15)-C(16)

121.0(2)

120.1(2)

119.6(2)

120.7(2)

122.7(2)

121.7(2)

107.7(2)

118.5(2)

119.9(2)

10c

C(1)-O(1)-C(12)

O(1)-C(1)-C(9)

O(2)-C(2)-C(3)

C(3)-C(4)-C(10)

C(6)-C(7)-C(8)

C(9)-C(8)-C(11)

C(8)-C(9)-C(10)

C(5)-C(10)-C(9)

C(12)-C(13)-C(18)

C(14)-C(15)-C(16)

C(13)-C(18)-C(17)

114.2(3)

119.8(4)

123.2(4)

122.3(4)

123.8(5)

124.2(4)

117.9(4)

120.4(4)

122.2(4)

120.5(6)

120.6(5)

C(2)-O(2)-C(19)

C(2)-C(1)-C(9)

C(1)-C(2)-C(3)

C(6)-C(5)-C(10)

C(7)-C(8)-C(9)

C(1)-C(9)-C(8)

C(4)-C(10)-C(5)

C(1)-C(12)-C(13)

C(14)-C(13)-C(18)

C(15)-C(16)-C(17)

116.9(4)

121.7(4)

120.4(4)

120.3(5)

118.5(4)

125.4(4)

120.1(4)

108.1(4)

117.7(2)

120.1(6)

O(1)-C(1)-C(2)

O(2)-C(2)-C(1)

C(2)-C(3)-C(4)

C(5)-C(6)-C(7)

C(7)-C(8)-C(11)

C(1)-C(9)-C(10)

C(4)-C(10)-C(9)

C(12)-C(13)-C(14)

C(13)-C(14)-C(15)

C(16)-C(17)-C(18)

118.5(4)

116.4(4)

119.3(4)

119.1(5)

117.4(4)

116.7(4)

119.5(2)

120.1(4)

120.7(5)

120.4(5)

a carbonyl group or the disappearance of a hydroxy group in

¹H or ¹³C-NMR spectra in comparison with starting materi-

als. For example, compounds 11a-f and 12a-c showed one

new typical signal at d 194.10-197.79 (C=O) in ¹³C-NMR in-

dicating the effect of oxidation. The molecular formula of

compounds 11a-f and 12a-c were demonstrated on the basis

of HREIMS. Moreover, ¹³C-NMR and DEPT spectra of 11d

showed 15 carbons and the presence of one methyl, two

Syntheses of Substituted Naphthalenes and Naphthols

J. Chin. Chem. Soc., Vol. 51, No. 3, 2004 591

Scheme III

OR₃R₁

MeO

iii

ii

i

OH

O

OH

15a-f

7a-f

11a-f

13

a. R₁=H, R₃=CH₃

d. R₁=CH₃, R₃=CH₃

b. R₁=H, R₃=C₂H₅

e. R₁=CH₃, R₃=C₂H₅

c. R₁=H, R₃=CH₂C₆H₅

f. R₁=CH₃, R₃=CH₂C₆H₅

OR₃

O

OH

MeO

R₃O

iii

ii

O

i

OH

MeO

CH₃

12a-c

CH₃

8a-c

16a-c

14

c. R₃=CH₂C₆H₅

a. R₃=CH₃

b. R₃=C₂H₅

^aConditions: (i) PCC or dMP, CH₂Cl₂, rt, 1h; (ii) 5 % Grubbs cat., 0.05 M CH₂Cl₂, rt. (iii) tautomerization

methoxy, four sp²olefinic, two sp²tertiary, one sp³tertiary,

sults of percentage yield are summarized in Table 8. The re-

sults are of some interest because naphthalenes and naphthols

may be useful precursors for the synthesis of potential medic-

inal agents.

four sp²quaternary, and one carbonyl carbon. COSY cross-

peaks indicated sequences of (a) CH₃-1¢ to H-1¢; (b) H-3¢ to

H-2¢; and (c) H-5 to H-6. Thus, the phenyl vinyl ketonen skel-

eton 11d could be determined. The undesired product from

the oxidation of 7a was identified as 3-(2-allyl-3,4-dimeth-

oxyphenyl)-1-propenal (11a-un), which was assigned by ¹H,

¹³C-NMR, and EI-MS. The detailed studies of oxidation of

7a-f or 8a-c with other different oxidizing agents are cur-

rently in progress in our laboratory, with results forthcoming.

Finally, using 5% mol Grubbs catalyst in 0.05 M anhydrous

CH₂Cl₂to undergo ring-closing olefin metathesis, followed

by tautomerization in situ, gave naphthols (15a-f, 16a-c) in-

stead of benzocyclohexenones (13, 14). The evidence of this

In conclusion, based on Claisen rearrangement, ring-

closing olefin metathesis, and related reactions such as Grig-

nard reagents, and PCC or dMP oxidation, we have estab-

lished a straightforward, versatile, and novel method of trans-

forming isovanillin into a number of substituted naphtha-

lenes (9a-f and 10a-c) and naphthols (15a-f and 16a-c). The

application of our synthetic strategy to various potential com-

pounds is currently in progress in our laboratory.

1

transformation can be easily observed in either H or ¹³C-

EXPERIMENTAL

NMR spectra. For example, compound 15a was found to

have the molecular formula C₁₂H₁₂O₃on the basis of high-

resolution mass measurement. In addition, it showed two sig-

nals of the methoxy group at d 3.98, and 3.99, and one broad

hydroxyl signal at d 5.65 (D₂O exchangeable), but no olefin

proton in ¹H-NMR. COSY cross-peaks indicated sequences

of (a) H-7 to H-8; and (b) H-3 to H-2 and H-4. ¹³C-NMR spec-

tra demonstrated 12 carbons and the presence of two methyls,

five sp²methines, and five sp²quaternary carbons. Notably,

no carbonyl carbon was observed in the ¹³C-NMR spectrum.

Apparently, compound 15a was aromatized to lead a naph-

General remarks

Melting points (Yanaco micro melting-point apparatus)

are uncorrected. ¹H and ¹³C-NMR spectra were obtained on a

Varian Gemini-200, Varian Unity plus 400 or Bruker Ad-

vance 600 Spectrometer. NOESY spectra experiments were

recorded on a Varian VXR-500. Chemical shifts were mea-

sured in parts per million with respect to TMS. Mass spectra

were recorded on a Chem/hp/middle instrument. High-re-

solution mass spectra were performed on JEOL JMS SX/SX

102A. X-ray crystallographic analysis was performed using a

Rigaku AFC7S diffractometer. Silica gel (70-230 mesh) for

column chromatography and the precoated silica gel plate (60

1

thol ring in situ during cylization. The selected H-NMR

spectral data of naphthols are summarized in Table 7. The re-

592 J. Chin. Chem. Soc., Vol. 51, No. 3, 2004

Huang et al.

Table 7. The Selected ¹H NMR Spectra of Substituted Naphthols (15a-f, 16a-c)

OR₃R₁

OH

8

MeO

R₃O

3

2

3

7

MeO

8

5

4

OH

15a-f

16a-c

OH

H-2

H-3

H-4

H-5

H-7

H-8

15a

15b

15c

15d

15e

15f

16a

16b

16c

5.45(br s)

5.67(br s)

5.45(br s)

5.35(br s)

5.27(br s)

5.64(br s)

5.37(br s)

5.47(br s)

5.50(br s)

6.68(d)

6.67(d)

6.66(d)

6.54(d)

6.55(d)

6.40(d)

6.70(d)

6.68(d)

6.65(d)

7.28(t)

7.27(t)

7.29(t)

6.95(d)

6.99(d)

6.91(d)

7.16(t)

7.15(t)

7.13(t)

7.26(d)

7.25(d)

7.70(d)

-

7.68(d)

7.70(d)

7.33(d)

7.22(d)

7.26(d)

7.09(d)

-

7.96(d)

7.94(d)

7.96(d)

8.02(d)

7.99(d)

8.01(d)

7.48(s)

7.54(s)

-

7.29(d)

7.28(d)

7.27(d)

7.10(s)

7.11(s)

-

Table 8. Yields (%) for Compounds 11, 12, 15, and 16 in Scheme III

Substituents

Vinyl ketones 11^aVinyl ketones 12^a

Naphthols 15^a

Naphthols 16^a

a R₁= H, R₃= Me

b R₁= H, R₃= Et

c R₁= H, R₃= Bn

d R₁= Me, R₃= Me

e R₁= Me, R₃= Et

f R₁= Me, R₃= Bn

a R₃= Me

65

60

58

63

60

69

72

69

62¹⁹

61

63

46

53

40

60¹⁹

68

b R₃= Et

c R₃= Bn

62

^aExcept for 15a¹⁹and 16a¹⁹, all vinyl ketones (11, 12) and naphthols (15, 16) are new compounds, whose

structures were confirmed by spectral data such as ¹H NMR, ¹³C NMR, MS, and HRMS.

F-254) for TLC were purchased from E. Merck Co. UV light

(254 nm) was used to detect spots on TLC plates after devel-

opment. 3-Hydroxy-4-methoxybenzaldehyde (isovanillin)

(1) purchased from TCI (Tokyo Kasei Industry) was directly

used without purification. Grubbs catalyst (first generation)

was purchased from Fluca Company.

benzaldehydes (2a-d), respectively. Work up as typical pro-

cedure and purification by chromatographic column (silica

gel, ethyl acetate/n-hexane = 1/5) gave various allyloxyiso-

vanillins (2a-d), respectively, in good yields.

3-Allyloxy-4-methoxybenzaldehyde (2a)^15a

Pure 2a (35.2 g, 92%) was obtained as pale yellow liq-

1

General procedure for preparing 3-allyloxy-4-methoxy-

benzaldehydes (2a-d)

uid, R_f0.36 (EA/n-hexane = 1/3); H-NMR (CDCl₃, 400

MHz) d 3.96 (s, 3H, OCH₃), 4.67 (ddd, J = 5.2 Hz, 1.2 Hz, 1.2

Hz, 2H, OCH₂CH=CH₂), 5.32 (ddt, J = 10.4 Hz, 1.2 Hz, 1.2

Hz, 1H, OCH₂CH=CH₂), 5.45 (ddt, J = 17.2 Hz, 1.2 Hz, 1.2

Hz, 1H, OCH₂CH=CH₂), 6.09 (ddt, J = 17.2 Hz, 10.4 Hz, 5.6

Hz, 1H, OCH₂CH=CH₂), 6.99, 7.46 (each d, J = 8.0 Hz, 1H,

ArH), 7.41 (s, 1H, ArH), 9.83 (s, 1H, CHO); ¹³C-NMR (CDCl₃,

100 MHz) d 56.08, 69.64, 110.62, 110.82, 118.51, 126.72,

129.94, 132.44, 148.45, 154.77, 190.76; (70 eV) m/z (rel. in-

As a general procedure, isovanillin (1) (31 g, 0.2 mol)

dissolved in anhydrous acetone (250 mL) was respectively

reacted with allyl bromide (18.6 mL, 0.22 mol), 1-bromo-2-

butene (23.5 mL, 0.23 mol), trans cinnamyl chloride (32.3

mL, 0.23 mol), and 1-bromo-3-methyl-2-butane (23.0 mL,

0.23 mol) in the presence of K₂CO₃(34.7 g, 0.25 mol) under

reflux for 8 hr to give the corresponding 3-allyloxy-4-alkoxy-

Syntheses of Substituted Naphthalenes and Naphthols

J. Chin. Chem. Soc., Vol. 51, No. 3, 2004 593

tensity, %) 192 (M⁺, 46), 188 (100), 173 (85), 151 (84), 145

(60), 127 (71), 95 (58).

C₁₃H₁₆O₃: 220.1099. Found: 220.1097.

General procedure for the preparation of 3a-b and 4b-d

Method A, 2a-d (0.15 mol) was gently boiled and

strongly stirred in neat; method B, 2a-d (0.15 mol) was

gently boiled and strongly stirred in decalin; method C, 2a-d

(0.15 mol) was gently boiled and strongly stirred in N,N-

diethylaniline. All of the above methods were carried out un-

der argon. After the end of each reaction, which was moni-

tored by TLC, (except method A), the giving solution was

concentrated in vacuo to remove decalin or N,N-diethyl-

aniline. And the resulting residue was subjected to chromato-

graphic column (n-hexane/EA = 3/1) to give pure 3a-b, and

4b-d. The percentage yield was calculated according to the

highest percentage yield among the three methods.

3-(2-Butenoxy)-4-methoxybenzaldehyde (2b)^15b

Pure 2b (36.2 g, 88%) was obtained as pale yellow liq-

1

uid; R_f0.37 (EA/n-hexane = 1/3); H-NMR (CDCl₃, 400

MHz) d 1.74 (dd, J = 6.2 Hz, 1.3 Hz, 3H, CH₃CH=CH-CH₂),

3.93 (s, 3H, OCH₃), 4.56 (dd, J = 6.0 Hz, 1.0 Hz, 2H,

CH₃CH=CHCH₂), 5.77 (dtd, J = 15.2 Hz, 6.0 Hz, 1.3 Hz, 1H,

CH₃CH=CHCH₂), 5.89 (dqt, J = 15.2 Hz, 6.2 Hz, 1.0 Hz, 1H,

CH₃CH=CHCH₂), 6.97 (d, J = 8.4 Hz, 1H, ArH), 7.40 (d, J =

2.0 Hz, 1H, ArH), 7.43 (dd, J = 8.4 Hz, 2.0 Hz, 1H, ArH),

9.83 (s, 1H, CHO); ¹³C-NMR (CDCl₃, 100 MHz) d 17.45

(CH₃), 55.70 (OCH₃), 69.11 (CH₃CH=CHCH₂), 110.23, 125.01,

126.20, 126.31, 129.63, 130.95, 148.27, 154.41, 190.40

(CHO); (70 eV) m/z (rel. intensity, %) 206 (M⁺, 5), 153 (10),

152 (100), 151 (69), 123 (7), 109 (5), 95 (6); HRMS calcd for

C₁₂H₁₄O₃: 206.0943. Found: 206.0940.

2-Allyl-3-hydroxy-4-methoxybenzaldehyde (3a)¹⁶

Pure 3a (26.5 g, 92%) was obtained as pale yellow

liquid; R_f0.47 (EA/n-hexane = 1/3); ¹H-NMR (CDCl₃, 400

MHz) d 3.75 (ddd, J = 6.0 Hz, 1.6 Hz, 1.6 Hz, 2H,

CH₂=CHCH₂Ar), 3.77 (s, 3H, OCH₃), 4.84 (ddd, J = 17.5 Hz,

1.6 Hz, 1.6 Hz, 1H, CH₂=CHCH₂Ar), 4.88 (ddd, J = 6.0 Hz,

1.6 Hz, 1.6 Hz, 1H, CH₂=CHCH₂Ar), 5.89 (ddt, J = 17.5 Hz,

10.6 Hz, 6.0 Hz, 1H, CH₂=CHCH₂Ar), 6.28 (br s, 1H, OH),

6.71 (d, J = 8.4 Hz, 1H, ArH), 7.27 (d, J = 8.4 Hz, 1H, ArH),

9.90 (s, 1H, CHO); ¹³C-NMR (CDCl₃, 100 MHz) d 28.08

(CH₂=CHCH₂Ar), 55.76 (OCH₃), 107.91, 114.96, 125.28,

127.31, 127.74, 136.07, 143.61, 150.80, 191.40 (CHO); EI-

MS (70 eV) m/z (rel. intensity, %) 192 (M⁺, 54), 177 (100),

159 (23), 149 (22), 143 (18), 131 (29), 115 (18), 103 (28), 91

(19); HRMS calcd for C₁₁H₁₂O₃: 192.0786. Found: 192.0779.

3-(3-Phenyl-2-propenoxy)-4-methoxybenzaldehyde (2c)^15b

Pure 2c (46.1 g, 86%) was obtained as pale yellow

liquid; R_f0.40 (EA/n-hexane = 1/3); ¹H-NMR (CDCl₃, 500

MHz) d 3.96 (s, 3H, OCH₃), 4.81 (dd, J = 6.0 Hz, 1.0 Hz,

2H, C₆H₅CH=CHCH₂O), 5.53 (dt, J = 15.2 Hz, 6.0 Hz, 1H,

C₆H₅CH=CHCH₂O), 6.75 (d,

J = 15.2 Hz, 1H,

C₆H₅CH=CHCH₂O), 6.98 (d, J = 8.8 Hz, 1H, ArH), 7.25-7.40

(m, 5H, C₆H₅), 7.42 (d, J = 2.0 Hz, 1H, ArH), 7.45 (dd, J = 8.8

Hz, 2.0 Hz, 1H, ArH), 9.84 (s, 1H, CHO); ¹³C-NMR (CDCl₃,

125 MHz) d 56.08 (OCH₃), 69.49 (OCH₂), 110.59, 110.69,

123.40, 126.60, 126.79, 127.93, 128.47, 129.93, 133.96,

136.13, 148.45, 154.74, 190.76 (CHO); EI-MS (70 eV) m/z

(rel. intensity, %) 268 (M⁺, 27), 178 (19), 177 (90), 165 (22),

164 (100), 162 (20), 149 (21), 136 (68), 135 (31), 115 (17), 93

(20), 91 (38).

3-Hydroxy-4-methoxy-2-(1-methyl-2-propenyl)benzalde-

hyde (3b)¹⁶

Pure 3b (14.8 g, 48%) was obtained as pale yellow liq-

1

3-(3-Methyl-2-butenoxy)-4-methoxybenzaldehyde (2d)

uid; R_f0.42 (EA/n-hexane = 1/3); H-NMR (CDCl₃, 200

Pure 2d (35.2 g, 92%) was obtained as pale yellow liq-

MHz) d 1.50 (d, J = 7.2 Hz, 3H, CH₂=CHCHCH₃Ar), 3.98 (s,

3H, OCH₃), 4.72 (m, 1H, CH₂=CHCHCH₃Ar), 5.08 (dd, J =

17.3 Hz, 1.8 Hz, 1H, CH₂=CHCHCH₃Ar), 5.12 (dd, J = 10.3

Hz, 1.8 Hz, 1H, CH₂=CHCH₃CHAr), 5.93 (br s, 1H, OH),

6.32 (ddd, J = 17.3 Hz, 10.3 Hz, 5.4 Hz, 1H, CH₂=CHCH-

CH₃Ar), 6.86 (d, J = 8.5 Hz, 1H, ArH), 7.46 (d, J = 8.5 Hz,

1H, ArH), 10.21 (s, 1H, CHO); ¹³C-NMR (CDCl₃, 50 MHz) d

19.11 (CH₂=CHCHCH₃Ar), 33.95 (CH₂=CHCHCH₃Ar),

56.13 (OCH₃), 108.08, 113.75, 125.01, 128.28, 132.90,

142.21, 143.85, 150.90, 191.76 (CHO); EI-MS (70 eV) m/z

(rel. intensity, %) 206 (M⁺, 16), 191 (100), 177 (20), 176 (19),

163 (26), 145 (16), 131 (21), 103 (19), 91 (18); HRMS calcd

1

uid; R_f0.39 (EA/n-hexane = 1/3); H-NMR (CDCl₃, 500

MHz) d 1.77, 1.79 [each s, 3H, (CH₃)₂C=CHCH₂], 3.95 (s,

3H, OCH₃), 4.64 [d, J = 6.0 Hz, 2H, (CH₃)₂C=CHCH₂], 5.53

[t, J = 6.0 Hz, 1H, (CH₃)₂C=CHCH₂], 6.98 (d, J = 8.5 Hz, 1H,

ArH), 7.42 (d, J = 2.0 Hz, 1H, ArH), 7.49 (dd, J = 8.5 Hz, 2.0

Hz, 1H, ArH), 9.84 (s, 1H, CHO); ¹³C-NMR (CDCl₃, 125

MHz) d 18.09, 25.70 (each CH₃), 55.96 (OCH₃), 65.56

[(CH₃)₂C=CHCH₂], 110.21, 110.32, 118.93, 126.51, 129.83,

138.39, 148.65, 154.67, 190.78 (CHO); EI-MS (70 eV) m/z

(rel. intensity, %) 220 (M⁺, 0.7), 153 (11), 152 (100), 151

(57), 137 (2), 123 (6), 119 (3), 95 (2); HRMS calcd for

594 J. Chin. Chem. Soc., Vol. 51, No. 3, 2004

Huang et al.

for C₁₂H₁₄O₃: 206.0943. Found: 206.0935.

calcd for C₁₃H₁₆O₃: 220.1099. Found: 220.1100.

2-[2-(E)-Butenyl]-5-hydroxy-4-methoxybenzaldehyde

(4b)¹⁶

General procedure for preparing of 5a-f and 6a-c

As the general procedure described, 3a (1.92 g, 0.01

mol), 3b (2.06 g, 0.01 mol), and 4b (2.06 g, 0.01 mol) were

respectively alkylated with corresponding methyl iodide,

ethyl iodide, and benzyl bromide. After work up and chro-

matographic purification (n-hexane/EA = 5/1), pure com-

pounds 5a-f and 6a-c were produced.

Pure 4b (11.1 g, 36%) was obtained as pale yellow liq-

1

uid; R_f0.34 (EA/n-hexane = 1/3); H-NMR (CDCl₃, 200

MHz) d 1.66 (dd, J = 6.2 Hz, 1.3 Hz, 3H, CH₃CH=CHCH₂Ar),

3.67 (dd, J = 6.0 Hz, 1.3 Hz, 2H, CH₃CH=CHCH₂Ar), 3.96 (s,

3H, OCH₃), 5.41 (dqd, J = 13.2 Hz, 6.2 Hz, 1.3 Hz, 1H,

CH₃CH=CHCH₂Ar), 5.61 (dtd, J = 13.2 Hz, 6.0 Hz, 1.3 Hz,

1H, CH₃CH=CHCH₂Ar), 5.68 (br s, 1H, OH), 6.70, 7.41

(each s, 1H, ArH), 10.13 (s, 1H, CHO); ¹³C-NMR (CDCl₃, 50

MHz) d 17.85 (CH₃), 34.84 (CH₃CH=CHCH₂Ar), 56.03

(OCH₃), 112.29, 115.59, 126.85, 127.39, 129.94, 137.55,

144.18, 151.22, 190.54 (CHO); EI-MS (70 eV) m/z (rel. in-

tensity, %) 206 (M⁺, 36), 191 (29), 177 (100), 164 (17), 145

(17), 136 (63), 131 (19), 117 (13), 115 (12), 103 (10), 91 (14);

HRMS calcd for C₁₂H₁₄O₃: 206.0943. Found: 206.0948.

2-Allyl-3,4-dimethoxybenzaldehyde (5a)^17a

Pure 5a (1.81 g, 88%) was obtained as pale yellow liq-

1

uid, R_f0.62 (EA/n-hexane = 1/3); H-NMR (CDCl₃, 200

MHz) d 3.73, 3.85 (each s, 3H, OCH₃), 3.78 (ddd, J = 5.8 Hz,

1.8 Hz, 1.8 Hz, 2H, CH₂=CHCH₂Ar), 4.84 (ddd, J = 17.0 Hz,

3.3 Hz, 1.8 Hz, 1H, CH₂=CHCH₂Ar), 4.93 (ddd, J = 10.3 Hz,

3.3 Hz, 1.8 Hz, 1H, CH₂=CHCH₂Ar), 5.94 (ddt, J = 17.0 Hz,

10.3 Hz, 5.8 Hz, 1H, CH₂=CHCH₂Ar), 6.85 (d, J = 8.6 Hz,

1H, ArH), 7.54 (d, J = 8.6 Hz, 1H, ArH), 9.95 (s, 1H, CHO);

¹³C-NMR (CDCl₃, 50 MHz) d 28.41 (CH₂=CHCH₂Ar),

55.50, 60.60 (each, OCH₃), 109.64, 115.24, 127.62, 128.88,

135.72, 136.91, 146.98, 157.22, 190.59 (CHO); EI-MS (70

eV) m/z (rel. intensity, %) 206 (M⁺, 58), 191 (100), 175 (38),

174 (19), 163 (21), 147 (22), 131 (27), 103 (33), 91 (32);

HRMS calcd for C₁₂H₁₄O₃: 206.0943. Found: 206.0935.

5-Hydroxy-4-methoxy-2-[3-(E)-phenyl-2-propenyl]benzal-

dehyde (4c)

Pure 4c was obtained (65% in method B, and 76% in

method C) as colorless liquid, R_f0.24 (EA/n-hexane = 1/3);

¹H-NMR (CDCl₃, 400 MHz) d 3.90 (d, J = 2.4 Hz, 2H,

C₆H₅CH=CHCH₂), 3.94 (s, 3H, OCH₃), 5.79 (br s, 1H, OH),

6.36 (m, 1H, C₆H₅CH=CH), 6.37 (m, 1H, C₆H₅CH=CH),

6.76, 7.43 (each s, 1H, ArH), 7.19-7.30 (m, 5H, C₆H₅), 10.13

(s, 1H, CHO); ¹³C-NMR (CDCl₃, 100 MHz) d 35.20, 56.08,

112.56, 116.54, 126.08, 127.24, 127.46, 128.47, 128.91,

131.26, 136.48, 137.11, 144.38, 151.25, 190.61 (CHO); EI-

MS (70 eV) m/z (rel. intensity, %) 268 (M⁺, 18), 178 (17), 177

(100), 165 (10), 164 (39), 162 (12), 136 (50), 91 (15); HRMS

calcd for C₁₇H₁₆O₃: 268.1099. Found: 268.1098.

2-Allyl-3-ethoxy-4-methoxybenzaldehyde (5b)

Pure 5b (1.76 g, 80%) was obtained as pale yellow liq-

1

uid; R_f0.55 (EA/n-hexane = 1/3); H-NMR (CDCl₃, 200

MHz) d 1.36 (t, J = 7.0 Hz, 3H, OCH₂CH₃), 3.84 (ddd, J = 5.8

Hz, 1.8 Hz, 1.8 Hz, 2H, CH₂=CHCH₂Ar), 3.89 (s, 3H, OCH₃),

3.96 (q, J = 7.0 Hz, 2H, OCH₂CH₃), 4.88 (ddd, J = 17.0 Hz,

3.3 Hz, 1.8 Hz, 1H, CH₂=CHCH₂Ar), 4.98 (ddd, J = 10.3 Hz,

3.3 Hz, 1.8 Hz, 1H, CH₂=CHCH₂Ar), 5.99 (ddt, J = 17.0 Hz,

10.3 Hz, 5.8 Hz, 1H, CH₂=CHCH₂Ar), 6.88 (d, J = 8.5 Hz,

1H, ArH), 7.57 (d, J = 8.5 Hz, 1H, ArH), 10.02 (s, 1H, CHO);

¹³C-NMR (CDCl₃, 50 MHz) d 16.09 (OCH₂CH₃), 29.33

(CH₂=CHCH₂Ar), 56.27 (OCH₃), 69.57 (OCH₂CH₃), 110.26,

115.98, 128.43, 129.34, 136.69, 137.68, 146.96, 158.11,

191.47 (CHO); EI-MS (70 eV) m/z (rel. intensity, %) 220

(M⁺, 67), 205 (100), 192 (32), 191 (37), 177 (98), 164 (31),

159 (38), 143 (34), 135 (46), 131 (57), 103 (73), 91 (52);

HRMS calcd for C₁₃H₁₆O₃: 220.1099. Found: 220.1104.

5-Hydroxy-4-methoxy-2-(3-methyl-2-butenyl)benzaldehy-

de (4d)

Pure 4d was obtained (79% by method A, 58% by

method B, and 80% by method C) as colorless liquid, R_f0.34

1

(EA/n-hexane = 1/3); H-NMR (CDCl₃, 400 MHz) d 1.73,

1.74 (each s, 3H, (CH₃)₂C=CHCH₂), 3.69 (d, J = 7.0 Hz, 2H,

(CH₃)₂C=CHCH₂), 3.95 (s, 3H, OCH₃), 5.24 (t, J = 7.0 Hz,

1H, (CH₃)₂C=CHCH₂), 5.57 (br s, 1H, OH), 6.71, 7.40 (each

s, 1H, ArH), 10.13 (s, 1H, CHO); ¹³C-NMR (CDCl₃, 100

MHz) d 17.95, 25.63, 30.62, 55.97, 111.91, 115.68, 123.08,

127.30, 132.73, 138.75, 144.02, 151.24, 190.64; EI-MS (70

eV) m/z (rel. intensity, %) 220 (M⁺, 52), 205 (59), 190 (12),

187 (10), 177 (64), 165 (12), 164 (46), 162 (16), 145 (16), 137

(20), 136 (100), 131 (12), 117 (10), 115 (15), 91 (14); HRMS

2-Allyl-3-benzyloxy-4-methoxybenzaldehyde (5c)^17b

Pure 5c (2.76 g, 98%) was obtained as pale yellow

liquid, R_f0.56 (EA/n-hexane = 1/3); ¹H-NMR (CDCl₃, 200

MHz) d 3.88 (ddd, J = 5.8 Hz, 1.8 Hz, 1.8 Hz, 2H,

Syntheses of Substituted Naphthalenes and Naphthols

J. Chin. Chem. Soc., Vol. 51, No. 3, 2004 595

CH₂=CHCH₂Ar), 3.92 (s, 3H, OCH₃), 4.91 (ddd, J = 17.0 Hz,

3.3 Hz, 1.8 Hz, 1H, CH₂=CHCH₂Ar), 4.99 (s, 2H, OCH₂C₆H₅),

5.02 (ddd, J = 10.3 Hz, 3.3 Hz, 1.8 Hz, 1H, CH₂=CHCH₂Ar),

6.01 (ddt, J = 17.0 Hz, 10.3 Hz, 5.8 Hz, 1H, CH₂=CHCH₂Ar),

6.94 (d, J = 8.5 Hz, 1H, ArH), 7.34-7.48 (m, 5H, OCH₂C₆H₅),

7.67 (d, J = 8.5 Hz, 1H, ArH), 10.06 (s, 1H, CHO); ¹³C-NMR

(CDCl₃, 50 MHz) d 29.41 (CH₂=CHCH₂Ar), 56.37 (OCH₃),

75.41 (OCH₂C₆H₅), 110.49, 116.21, 128.57, 128.72, 128.85,

128.96, 129.69, 136.90, 137.71, 137.96, 146.59, 158.12,

191.42 (CHO); (70 eV) m/z (rel. intensity, %) 282 (M⁺, 0.2),

192 (2), 191 (20), 177 (8), 163 (2), 159 (2), 135 (3), 131 (2),

105 (2), 103 (4), 92 (10), 91 (100); HRMS calcd for

C₁₈H₁₈O₃: 282.1256. Found: 282.1259.

(27), 91 (31); HRMS calcd for C₁₄H₁₈O₃: 234.1256. Found:

234.1252.

3-Benzyloxy-4-methoxy-2-(1-methyl-2-propenyl)benzalde-

hyde (5f)

Pure 5f (2.87 g, 97%) was obtained as pale yellow liq-

1

uid, R_f0.67 (EA/n-hexane = 1/3); H-NMR (CDCl₃, 200

MHz) d 1.43 (d, J = 7.2 Hz, 3H, CH₂=CHCH₃CHAr), 3.96 (s,

3H, OCH₃), 4.55 (m, 1H, CH₂=CHCH₃CHAr), 4.98 (ddd, J =

17.3 Hz, 2.4 Hz, 1.2 Hz, 1H, CH₂=CHCH₃CHAr), 4.99 (s,

2H, OCH₂C₆H₅), 5.06 (ddd, J = 10.3 Hz, 2.4 Hz, 1.2 Hz, 1H,

CH₂=CHCH₃CHAr), 6.26 (ddd, J = 17.3 Hz, 10.3 Hz, 4.4 Hz,

1H, CH₂=CHCH₃CHAr), 6.94 (d, J = 8.6 Hz, 1H, ArH),

7.35-7.44 (m, 5H, OCH₂C₆H₅), 7.77 (d, J = 8.6 Hz, 1H, ArH),

10.29 (s, 1H, CHO); ¹³C-NMR (CDCl₃, 50 MHz) d 20.81

(CH₂=CHCH₃CHAr), 33.62 (CH₂=CHCH₃CHAr), 55.81

(OCH₃), 74.90 (OCH₂C₆H₅), 109.95, 113.67, 127.42, 128.04,

128.17, 128.41, 128.70, 137.20, 142.31, 143.13, 145.39,

157.41, 191.06 (CHO); EI-MS (70 eV) m/z (rel. intensity, %)

296 (M⁺, 0.2), 278 (0.7), 206 (2), 205 (20), 191 (5), 188 (2),

177 (6), 174 (2), 173 (2), 161 (1), 145 (6), 117 (4), 92 (9), 91

(100); HRMS calcd for C₁₉H₂₀O₃: 296.1412. Found: 296.1408.

3,4-Dimethoxy-2-(1-methyl-2-propenyl)benzaldehyde (5d)

Pure 5d (2.02 g, 92%) was obtained as pale yellow liq-

1

uid, R_f0.64 (EA/n-hexane = 1/3); H-NMR (CDCl₃, 200

MHz) d 1.48 (d, J = 7.3 Hz, 3H, CH₂=CHCH₃CHAr), 3.78,

3.91 (each s, 3H, OCH₃), 4.56 (m, 1H, CH₂=CHCH₃CHAr),

4.99 (ddd, J = 17.3 Hz, 2.4 Hz, 1.2 Hz, 1H, CH₂=CHCH₃CHAr),

5.06 (ddd, J = 10.3 Hz, 2.4 Hz, 1.2 Hz, 1H, CH₂=CHCH₃CHAr),

6.22 (ddd, J = 17.3 Hz, 10.3 Hz, 4.8 Hz, 1H, CH₂=CHCH₃CHAr),

6.88 (d, J = 8.6 Hz, 1H, ArH), 7.68 (d, J = 8.6 Hz, 1H, ArH),

10.23 (s, 1H, CHO); ¹³C-NMR (CDCl₃, 50 MHz) d 20.62

(CH₂=CHCH₃CH), 33.68 (CH₂=CHCH₃CH), 55.72, 60.87

(each, OCH₃), 109.88, 113.57, 127.82, 128.06, 141.91, 143.06,

146.99, 157.42, 191.02 (CHO); EI-MS (70 eV) m/z (rel. in-

tensity, %) 220 (M⁺, 15), 205 (100), 191 (19), 177 (23), 161

(15), 115 (14), 91 (14); HRMS calcd for C₁₃H₁₆O₃: 220.1099.

Found: 220.1105.

2-(2-Butenyl)-4,5-dimethoxybenzaldehyde (6a)

Pure 6a (1.83 g, 83%) was obtained as pale yellow liq-

1

uid; R_f0.63 (EA/n-hexane = 1/3); H-NMR (CDCl₃, 200

MHz) d 1.66 (dd, J = 6.2 Hz, 1.3 Hz, 3H, CH₃CH=CHCH₂Ar),

3.67 (d, J = 6.0 Hz, 2H, CH₃CH=CHCH₂Ar), 3.91, 3.95 (each

s, 3H, OCH₃), 5.43 (dq, J = 13.2 Hz, 6.2 Hz, 1H,

CH₃CH=CHCH₂Ar), 5.64 (dtd, J = 13.2 Hz, 6.0 Hz, 1.3 Hz,

1H, CH₃CH=CHCH₂Ar), 6.72, 7.39 (each s, 1H, ArH), 10.19

(s, 1H, CHO); ¹³C-NMR (CDCl₃, 50 MHz) d 17.58 (CH₃),

34.24 (CH₃CH=CHCH₂Ar), 55.68, 55.76 (each, OCH₃),

110.36, 112.55, 126.48, 126.68, 129.74, 138.44, 147.49,

153.63, 189.64 (CHO); EI-MS (70 eV) m/z (rel. intensity, %)

220 (M⁺, 65), 205 (35), 191 (100), 178 (21), 150 (91), 91 (22);

HRMS calcd for C₁₃H₁₆O₃: 220.1099. Found: 220.1099.

3-Ethoxy-4-methoxy-2-(1-methyl-2-propenyl)benzaldehy-

de (5e)

Pure 5e (1.87 g, 80%) was obtained as pale yellow liq-

1

uid, R_f0.71 (EA/n-hexane = 1/3); H-NMR (CDCl₃, 400

MHz) d 1.39 (t, J = 7.2 Hz, 3H, OCH₂CH₃), 1.51 (d, J = 7.2

Hz, 3H, CH₂=CHCH₃CHAr), 3.92 (s, 3H, OCH₃), 4.03 (q, J =

7.2 Hz, 2H, OCH₂CH₃), 4.59 (m, 1H, CH₂=CHCH₃CHAr),

5.03 (ddd, J = 17.3 Hz, 2.4 Hz, 1.2 Hz, 1H, CH₂=CHCH₃CHAr),

5.08 (ddd, J = 10.3 Hz, 2.4 Hz, 1.2 Hz, 1H, CH₂=CHCHAr),

6.25 (ddd, J = 17.3 Hz, 10.3 Hz, 4.4 Hz, 1H, CH₂=CHCH₃CHAr),

6.90 (d, J = 8.6 Hz, 1H, ArH), 7.72 (d, J = 8.6 Hz, 1H, ArH),

10.28 (s, 1H, CHO); ¹³C-NMR (CDCl₃, 100 MHz) d 15.40

(OCH₂CH₃), 20.73 (CH₂=CHCHCH₃), 33.50 (CH₂=CHCHAr),

55.67 (OCH₃), 68.93 (OCH₂CH₃), 109.72, 113.51, 127.27,

128.10, 141.95, 143.14, 145.87, 157.44, 191.00 (CHO);

EI-MS (70 eV) m/z (rel. intensity, %) 234 (M⁺, 25), 219 (100),

205 (30), 191 (62), 177 (36), 163(25), 145 (35), 117 (34), 115

2-(2-Butenyl)-5-ethoxy-4-methoxybenzaldehyde (6b)

Pure 6b (1.97 g, 84%) was obtained as pale yellow liq-

1

uid; R_f0.70 (EA/n-hexane = 1/3); H-NMR (CDCl₃, 200

MHz) d 1.48 (t, J = 7.0 Hz, 3H, OCH₂CH₃), 1.66 (dd, J = 6.2

Hz, 1.3 Hz, 3H, CH₃CH=CHCH₂), 3.67 (d, J = 6.0 Hz, 2H,

CH₃CH=CHCH₂), 3.94 (s, 3H, OCH₃), 4.15 (q, J = 7.0 Hz,

2H, OCH₂CH₃), 5.44 (dq, J = 13.2 Hz, 6.2 Hz, 1H,

CH₃CH=CHCH₂Ar), 5.63 (dtd, J = 13.2 Hz, 6.0 Hz, 1.3 Hz,

1H, CH₃CH=CHCH₂Ar), 6.70, 7.38 (each s, 1H, ArH), 10.18

(s, 1H, CHO); ¹³C-NMR (CDCl₃, 60 MHz) d 14.63 (OCH₂CH₃),

596 J. Chin. Chem. Soc., Vol. 51, No. 3, 2004

Huang et al.

17.83 (CH₃), 34.59 (CH₃CH=CHCH₂Ar), 56.04, 64.39

(OCH₂CH₃), 111.84, 112.89, 126.69, 126.95, 129.95, 138.54,

147.01, 154.13, 190.05 (CHO); EI-MS (70 eV) m/z (rel. in-

tensity, %): 234 (M⁺, 71), 205 (100), 191 (40), 177 (68), 164

(51), 145 (25), 136 (61), 131 (31), 115 (25), 103 (16), 91 (27);

HRMS calcd for C₁₄H₁₈O₃: 234.1256. Found: 234.1256.

6.02 (ddd, J = 17.2 Hz, 10.6 Hz, 5.8 Hz, 1H, CH₂=CHCH(OH)Ar),

6.81, 7.14 (each d, J = 8.4 Hz, 1H, H-5 and H-6); ¹³C-NMR

(CDCl₃, 100 MHz) d 29.63 (CH₂=CHCH₂), 55.35, 60.64

(OCH₃), 70.50 (CHOH), 110.43, 114.29, 115.01, 122.43,

131.26, 133.91, 137.49, 139.95, 146.96, 152.01; EI-MS (70

eV) m/z (rel. intensity, %) 234 (M⁺, 82), 207 (100), 205 (55),

191 (66), 185 (66), 176 (55), 175 (95), 174 (66), 161 (52), 159

(52), 158 (56), 131 (56), 115 (90), 91 (72); HRMS: calcd for

C₁₄H₁₈O₃: 234.1256. Found: 234.1249.

5-Benzyloxy-2-(2-butenyl)-4-methoxybenzaldehyde (6c)

Pure 6c (2.58 g, 87%) was obtained as pale yellow liq-

1

uid; R_f0.70 (EA/n-hexane = 1/3); H-NMR (CDCl₃, 200

MHz) d 1.66 (dd, J = 6.2 Hz, 1.3 Hz, 3H, CH₃CH=CH-

CH₂Ar), 3.66 (d, J = 6.0 Hz, 2H, CH₃CH=CHCH₂Ar), 3.94 (s,

3H, OCH₃), 5.16 (s, 2H, OCH₂C₆H₅), 5.42 (dq, J = 13.2 Hz,

6.2 Hz, 1H, CH₃CH=CHCH₂Ar), 5.60 (dtd, J = 13.2 Hz, 6.0

Hz, 1.3 Hz, 1H, CH₃CH=CHCH₂Ar), 6.72, 7.44 (each s, 1H,

ArH), 7.33-7.46 (m, 5H, OCH₂C₆H₅), 10.15 (s, 1H, CHO);

¹³C-NMR (CDCl₃, 50 MHz) d 17.85 (CH₃), 34.62

(CH₃CH=CHCH₂Ar), 56.06 (OCH₃), 70.92 (OCH₂C₆H₅),

113.13, 113.20, 126.65, 127.01, 127.48, 128.01, 128.57,

129.87, 136.51, 139.01, 146.83, 154.48, 189.99 (CHO);

EI-MS (70 eV) m/z (rel. intensity, %) 296 (M⁺, 2), 205 (11),

177 (8), 149 (2), 131 (3), 117 (2), 115 (2), 91 (100); HRMS

calcd for C₁₉H₂₀O₃: 296.1412. Found: 296.1410.

1-(2-Allyl-3-ethoxy-4-methoxyphenyl)-2-propen-1-ol (7b)

Pure 7b (1.13 g, 91%) was obtained as colorless liquid,

R_f= 0.53 (EA/n-hexane = 1/3); ¹H-NMR (CDCl₃, 600 MHz)

d: 1.36 (t, J = 7.2 Hz, 3H, OCH₂CH₃), 2.11 (br s, 1H, OH, D₂O

exchangeable), 3.50 (ddd, J = 5.4 Hz, 1.8 Hz, 1.8 Hz, 2H,

CH₂=CHCH₂Ar), 3.82 (s, 3H, OCH₃), 3.98 (q, J = 7.2 Hz, 2H,

OCH₂CH₃), 4.91 (ddt, J = 16.8 Hz, 2.0 Hz, 1.8 Hz, 1H,

CH₂=CHCH₂Ar), 5.01 (ddt, J = 9.9 Hz, 2.0 Hz, 1.8 Hz, 1H,

CH₂=CHCH₂Ar), 5.17 (ddd, J = 10.2 Hz, 1.2 Hz, 1.2 Hz, 1H,

CH₂=CHCH-(OH)Ar), 5.31 (ddd, J = 16.8 Hz, 1.2 Hz, 1.2 Hz,

1H, CH₂=CHCH(OH)Ar), 5.35 (br s, 1H, CH₂=CHCH(OH)Ar),

5.97 (ddt, J = 16.8 Hz, 9.9 Hz, 5.4 Hz, 1H, CH₂=CHCH₂Ar),

6.03 (ddd, J = 16.8 Hz, 10.2 Hz, 6.0 Hz, 1H, CH₂=CHCH-

(OH)Ar), 6.80, 7.13 (each d, J = 8.4 Hz, 1H, H-5 and H-6);

¹³C-NMR (CDCl₃, 150 MHz) d: 15.43 (OCH₂CH₃), 29.69

(CH₂=CHCH₂), 55.35 (OCH₃), 68.58 (OCH₂CH₃), 70.58

(CHOH), 110.23, 114.07, 115.11, 122.17, 131.23, 133.33,

137.43, 139.95, 146.05, 151.97; EI-MS (70 eV) m/z (rel. in-

tensity, %) 248 (M⁺, 70), 221 (60), 177 (43), 175 (43), 173

(44), 161 (54), 159 (80), 147 (41), 145 (42), 143 (80), 141

(43), 131 (84), 115 (90), 103 (65), 91 (63); HRMS: calcd for

C₁₅H₂₀O₃: 248.1412. Found: 248.1409.

General procedure for preparing 7a-f and 8a-c

Each of the compounds 5a-f and 6a-c (5 mmol) dis-

solved in anhydrous THF (30 mL) was added with vinyl mag-

nesium bromide (1.0 M, 5.5 mL), and the mixture was stirred

at room temperature for 2 h. The solution was then quenched

with saturated NH₄Cl_(aq)solution and extracted with ethyl ac-

etate (15 mL ´ 5). The extracted solution was washed with

brine (10 mL ´ 2), and dried with anhydrous MgSO₄, and fil-

tered. The filtrate was concentrated in vacuo, and the given

residue was subjected to chromatographic column (silica gel,

n-hexane/EA = 3/1) to give the pure 7a-f and 8a-c.

1-(2-Allyl-3-benzyloxy-4-methoxyphenyl)-2-propen-1-ol

(7c)

Pure 7c (1.47 g, 95%) was obtained as colorless liquid,

R_f= 0.45 (EA/n-hexane = 1/3); ¹H-NMR (CDCl₃, 400 MHz)

d: 2.09 (br s, 1H, OH, D₂O exchangeable), 3.37 (ddd, J = 5.4

Hz, 1.8 Hz, 1.8 Hz, 2H, CH₂=CHCH₂Ar), 3.75 (s, 3H, OCH₃),

4.79 (ddt, J = 17.4 Hz, 2.0 Hz, 1.8 Hz, 1H, CH₂=CHCH₂Ar),

4.87 (s, 2H, OCH₂C₆H₅), 4.90 (ddt, J = 10.4 Hz, 2.0 Hz, 1.8

Hz, 1H, CH₂=CHCH₂Ar), 5.07 (ddd, J = 10.6 Hz, 1.2 Hz, 1.2

Hz, 1H, CH₂=CHCH(OH)Ar), 5.20 (ddd, J = 17.2 Hz, 1.2

Hz, 1.2 Hz, 1H, CH₂=CH-CH(OH)Ar), 5.24 (br s, 1H,

CH₂=CHCH(OH)Ar), 5.91 (ddt, J = 17.4 Hz, 10.4 Hz, 5.4 Hz,

1H, CH₂=CHCH₂Ar), 6.02 (ddd, J = 17.2 Hz, 10.6 Hz, 5.8

Hz, 1H, CH₂=CHCH(OH)Ar), 6.74, 7.07 (each d, J = 8.4 Hz,

1-(2-Allyl-3,4-dimethoxyphenyl)-2-propen-1-ol (7a)

Pure 7a (1.12 g, 96%) was obtained as colorless liquid,

R_f= 0.54 (EA/n-hexane = 1/3); ¹H-NMR (CDCl₃, 400 MHz)

d 2.15 (br s, 1H, OH, D₂O exchangeable), 3.53 (ddd, J = 5.4

Hz, 1.8 Hz, 1.8 Hz, 2H, CH₂=CHCH₂Ar), 3.78, 3.83 (each s,

3H, OCH₃), 4.90 (ddt, J = 17.4 Hz, 2.0 Hz, 1.8 Hz, 1H,

CH₂=CHCH₂Ar), 5.01 (ddt, J = 10.4 Hz, 2.0 Hz, 1.8 Hz, 1H,

CH₂=CHCH₂Ar), 5.16 (ddd, J = 10.6 Hz, 1.2 Hz, 1.2 Hz, 1H,

CH₂=CHCH(OH)Ar), 5.31 (ddd, J = 17.2 Hz, 1.2 Hz, 1.2 Hz,

1H, CH₂=CHCH(OH) Ar), 5.33 (br s, 1H, CH₂=CHCH(OH)Ar),

5.94 (ddt, J = 17.4 Hz, 10.4 Hz, 5.4 Hz, 1H, CH₂=CHCH₂Ar),

Syntheses of Substituted Naphthalenes and Naphthols

J. Chin. Chem. Soc., Vol. 51, No. 3, 2004 597

1H, H-5 and H-6), 7.21-7.36 (m, 5H, OCH₂C₆H₅); ¹³C-NMR

(CDCl₃, 100 MHz) d: 29.84 (CH₂=CHCH₂), 55.58 (OCH₃),

70.76 (CHOH), 74.57 (OCH₂C₆H₅), 110.52, 114.37, 115.11,

122.61, 127.68, 127.86, 128.18, 128.21, 131.55, 133.96,

137.49, 139.92, 145.88, 152.18; EI-MS (70 eV) m/z (rel. in-

tensity, %) 310 (M⁺, 3), 201 (6), 177 (5), 175 (4), 169 (4), 161

(5), 160 (7), 159 (5), 145 (4), 143 (5), 141 (5), 131 (10), 129

(4), 128 (4), 115 (9), 103 (6), 92 (8), 91 (100); HRMS: calcd.

for C₂₀H₂₂O₃: 310.1569. Found: 310.1562.

1-[3-Ethoxy-4-methoxy-2-(1-methylallyl)phenyl]-2-propen-

1-ol (7e)

7e (1.07 g, 82%) was isolated as pale yellow liquid in a

3:2 mixture of diastereomers, R_f= 0.64 (EA/n-hexane = 1/3);

¹H-NMR (CDCl₃, major diastereomer 400 MHz) d: 1.37 (t, J

= 7.2 Hz, 3H, OCH₂CH₃), 1.47 (d, J = 7.2 Hz, 3H,

CH₂=CHCH₃CHAr), 1.90 (br s, 1H, OH, D₂O exchangeable),

3.83 (s, 3H, OCH₃), 4.00 (q, J = 7.2 Hz, 2H, OCH₂CH₃), 4.19

(m, 1H, CH₂=CH(CH₃)CHAr), 5.04 (ddd, J = 10.3 Hz, 2.4

Hz, 1.2 Hz, 1H, CH₂=CH(CH₃)CH), 5.06 (ddd, J = 17.3 Hz,

2.4 Hz, 1.2 Hz, 1H, CH₂=CH(CH₃)CH), 5.18 (ddd, J = 10.6

Hz, 1.2 Hz, 1.2 Hz, 1H, CH₂=CHCH), 5.33 (ddd, J = 17.2 Hz,

1.2 Hz, 1.2 Hz, 1H, CH₂=CHCH), 5.51 (br s, 1H,

CH₂=CHCH), 6.08 (ddd, J = 17.2 Hz, 10.6 Hz, 5.8 Hz, 1H,

CH₂=CHCH), 6.22 (ddd, J = 17.3 Hz, 10.3 Hz, 4.8 Hz, 1H,

CH₂=CHCH₃CHAr), 6.82, 7.11 (each d, J = 8.8 Hz, 1H,

ArH); ¹³C-NMR (CDCl₃, major diastereomer 100 MHz) d

15.49 (OCH₂CH₃), 19.33 (CH₂=CHCH₃CHAr), 34.84

(CH₂=CHCH₃CHAr), 55.59 ( OCH₃), 68.52 (OCH₂CH₃),

70.75, 110.46, 112.82, 114.10, 123.23, 133.64, 137.52,

1-[3,4-Dimethoxy-2-(1-methylallyl)phenyl]-2-propen-1-ol

(7d)

7d (0.97 g, 78%) was isolated as pale yellow liquid in a

3:2 mixture of diastereomers, R_f= 0.55 (EA/n-hexane = 1/3);

¹H-NMR (CDCl₃, major diastereomer 400 MHz) d 1.44 (d, J

= 7.2 Hz, 3H, CH₂=CH(CH₃)CH), 2.13 (br s, 1H, OH, D₂O

exchangeable), 3.79, 3.83 (each s, 3H, OCH₃), 4.10 (m, 1H,

CH₂=CH(CH₃)CH), 5.00 (ddd, J = 10.3 Hz, 2.4 Hz, 1.2 Hz,

1H, CH₂=CH(CH₃)CH), 5.05 (ddd, J = 17.3 Hz, 2.4 Hz, 1.2

Hz, 1H, CH₂=CH(CH₃)CH), 5.18 (ddd, J = 10.6 Hz, 1.2 Hz,

1.2 Hz, 1H, CH₂=CHCH-(OH)Ar), 5.31 (ddd, J = 17.2 Hz,

1.2 Hz, 1.2 Hz, 1H, CH₂=CHCH(OH)Ar), 5.47 (br s, 1H,

CH₂=CHCH(OH)Ar), 6.06 (ddd, J = 17.2 Hz, 10.6 Hz, 5.8

Hz, 1H, CH₂=CHCH-(OH)Ar), 6.21 (ddd, J = 17.3 Hz, 10.3

Hz, 4.8 Hz, 1H, CH₂=CH(CH₃)CH), 6.80, 7.12 (each d, J = 8.8

Hz, 1H, ArH); ¹³C-NMR (CDCl₃, major diastereomer 100 MHz)

d 19.28 (CH₂=CH(CH₃)CHAr), 35.26 (CH₂=CH(CH₃)CHAr),

55.52, 60.61 (each, OCH₃), 70.95, 110.41, 112.79, 114.22,

123.11, 133.38, 137.52, 140.21, 143.35, 147.40, 152.35; ¹H-

NMR (CDCl₃, minor diastereomer 400 MHz) d 1.41 (d, J =

7.2 Hz, 3H, CH₂=CH(CH₃)CH), 2.08 (br s, 1H, OH, D₂O ex-

changeable), 3.79, 3.83 (each s, 3H, OCH₃), 4.10 (m, 1H,

CH₂=CH(CH₃)CH), 4.99 (ddd, J = 10.3 Hz, 2.4 Hz, 1.2 Hz,

1H, CH₂=CH(CH₃)CH), 5.03 (ddd, J = 17.3 Hz, 2.4 Hz, 1.2

Hz, 1H, CH₂=CH-(CH₃)CH), 5.18 (ddd, J = 10.6 Hz, 1.2 Hz,

1.2 Hz, 1H, CH₂=CHCH(OH)Ar), 5.28 (ddd, J = 17.2 Hz, 1.2

Hz, 1.2 Hz, 1H, CH₂=CHCH(OH)Ar), 5.47 (br s, 1H,

CH₂=CH-CH(OH)Ar), 6.02 (ddd, J = 17.2 Hz, 10.6 Hz, 5.8

Hz, 1H, CH₂=CHCH(OH)Ar), 6.16 (ddd, J = 17.3 Hz, 10.3

Hz, 4.8 Hz, 1H, CH₂=CH(CH₃)CHAr), 6.80, 7.12 (each d, J =

8.8 Hz, 1H, ArH); ¹³C-NMR (CDCl₃, minor diastereomer 100

MHz) d 19.69 (CH₂=CH(CH₃)CH), 35.36 (CH₂=CH(CH₃)CH),

55.52, 60.61 (each, OCH₃), 70.95, 110.45, 112.85, 114.37,

123.38, 133.36, 137.32, 140.25, 143.46, 147.40, 152.39;

EI-MS (70 eV) m/z (rel. intensity, %) 248 (M⁺, 40), 221 (50),

215 (41), 205 (41), 199 (40), 189 (100), 188 (51), 174 (41),

115 (61); HRMS: calcd. for C₁₅H₂₀O₃: 248.1412. Found:

248.1410.

1

140.24, 143.47, 146.23, 152.45; H-NMR (CDCl₃, minor

diastereomer 400 MHz) d 1.42 (t, J = 7.2 Hz, 3H, OCH₂CH₃),

1.42 (d, J = 7.2 Hz, 3H, CH₂=CHCH₃CHAr), 1.81 (br s, 1H,

OH, D₂O exchangeable), 3.83 (s, 3H, OCH₃), 3.98 (q, J = 7.2

Hz, 2H, OCH₂CH₃), 4.19 (m, 1H, CH₂=CH(CH₃)CHAr), 5.00

(ddd, J = 10.3 Hz, 2.4 Hz, 1.2 Hz, 1H, CH₂=CH(CH₃)CH),

5.03 (ddd, J = 17.3 Hz, 2.4 Hz, 1.2 Hz, 1H, CH₂=CH-

(CH₃)CH), 5.18 (ddd, J = 10.6 Hz, 1.2 Hz, 1.2 Hz, 1H,

CH₂=CHCH), 5.30 (ddd, J = 17.2 Hz, 1.2 Hz, 1.2 Hz, 1H,

CH₂=CHCH), 5.51 (br s, 1H, CH₂=CHCH), 6.04 (ddd, J =

17.2 Hz, 10.6 Hz, 5.8 Hz, 1H, CH₂=CHCH), 6.18 (ddd, J =

17.3 Hz, 10.3 Hz, 4.8 Hz, 1H, CH₂=CHCH₃CHAr), 6.80, 7.13

(each d, J = 8.8 Hz, 1H, ArH); ¹³C-NMR (CDCl₃, minor

diastereomer 100 MHz) d 15.49 (OCH₂CH₃), 19.79

(CH₂=CHCH₃CH), 35.00 (CH₂=CHCH₃CH), 55.59 (OCH₃),

68.56 (OCH₂CH₃), 70.75, 110.51, 112.88, 114.32, 123.56,

133.75, 137.60, 140.28, 143.64, 146.35, 152.54; EI-MS (70

eV) m/z (rel. intensity, %) 262 (M⁺, 72), 235 (60), 203 (77),

175 (58), 173 (70), 169 (51), 159 (71), 157 (80), 145 (61), 143

(51), 131 (70), 129 (68), 128 (57), 115 (100), 91 (60); HRMS:

calcd. for C₁₆H₂₂O₃: 262.1569. Found: 262.1577.

1-[3-Benzloxy-4-methoxy-2-(1-methylallyl)phenyl]-2-

propen-1-ol (7f)

7f (1.30 g, 80%) was isolated as pale yellow liquid in a

3:2 mixture of diastereomers, R_f= 0.60 (EA/n-hexane = 1/3);

¹H-NMR (CDCl₃, major diastereomer 400 MHz) d 1.42 (d, J

= 7.2 Hz, 3H, CH₂=CH(CH₃)CHAr), 1.98 (br s, 1H, OH),

598 J. Chin. Chem. Soc., Vol. 51, No. 3, 2004

Huang et al.

3.86 (s, 3H, OCH₃), 4.11 (m, 1H, CH₂=CH(CH₃)CHAr), 4.99

(ddd, J = 10.3 Hz, 2.4 Hz, 1.2 Hz, 1H, CH₂=CH(CH₃)CH),

4.97 (s, 2H, OCH₂C₆H₅), 5.03 (ddd, J = 17.3 Hz, 2.4 Hz, 1.2

Hz, 1H, CH₂=CH(CH₃)CH), 5.19 (ddd, J = 10.6 Hz, 1.2 Hz,

1.2 Hz, 1H, CH₂=CHCH), 5.33 (ddd, J = 17.2 Hz, 1.2 Hz, 1.2

Hz, 1H, CH₂=CHCH), 5.51 (br s, 1H, CH₂=CHCH), 6.07

(ddd, J = 17.2 Hz, 10.6 Hz, 5.6 Hz, 1H, CH₂=CHCH), 6.18

(ddd, J = 17.3 Hz, 10.3 Hz, 4.8 Hz, 1H, CH₂=CHCH₃CHAr),

6.85, 7.15 (each d, J = 8.8 Hz, 1H, ArH), 7.31-7.47 (m, 5H,

OCH₂C₆H₅); ¹³C-NMR (CDCl₃, major diastereomer 100

MHz) d 19.35 (CH₂=CH(CH₃)CH), 34.84 (CH₂=CH(CH₃)CH),

55.67 (OCH₃), 70.70, 74.42 (OCH₂C₆H₅), 110.62, 112.99,

114.14, 123.66, 127.71, 127.92, 128.31, 133.78, 133.90,

114.39, 126.11, 130.07, 130.16, 132.36, 139.86, 147.40,

148.11; EI-MS (70 eV) m/z (rel. intensity, %) 248 (M⁺, 94),

230 (66), 215 (76), 206 (55), 205 (51), 191 (74), 189 (72), 188

(70), 175 (81), 151 (54), 115 (84), 91 (59); HRMS: calcd. for

C₁₅H₂₀O₃: 248.1412. Found: 248.1411.

1-(2-Butenyl-5-ethoxy-4-methoxyphenyl)-2-propen-1-ols

(8b)

Pure 8b (1.10 g, 84%) was obtained as pale yellow liq-

1

uid, R_f= 0.50 (EA/n-hexane = 1/3); H-NMR (CDCl₃, 400

MHz) d 1.43 (t, J = 7.2 Hz, 3H, OCH₂CH₃), 1.67 (dd, J = 6.4

Hz, 1.3 Hz, 3H, CH₃CH=CHCH₂Ar), 2.11 (br s, 1H, OH),

3.32 (d, J = 6.0 Hz, 2H, CH₃CH=CHCH₂Ar), 3.84 (s, 3H,

OCH₃), 4.07 (q, J = 7.2 Hz, 2H, OCH₂CH₃), 5.17 (ddd, J =

10.4 Hz, 1.6 Hz, 1.2 Hz, 1H, CH₂=CHCHOH), 5.30 (ddd, J =

17.2 Hz, 1.6 Hz, 1.2 Hz, 1H, CH₂=CHCHOH), 5.39 (br s, 1H,

CH₂=CHCHOH), 5.43 (dq, J = 13.2 Hz, 6.2 Hz, 1H,

CH₃CH=CHCH₂Ar), 5.56 (dtq, J = 13.2 Hz, 6.0 Hz, 1.3 Hz,

1H, CH₃CH=CHCH₂Ar), 6.00 (ddd, J = 17.2 Hz, 10.4 Hz, 4.6

Hz, 1H, CH₂=CHCHOH), 6.65, 6.96 (each s, 1H, ArH);

¹³C-NMR (CDCl₃, 100 MHz) d 14.70 (OCH₂CH₃), 17.71

(CH₃), 35.11 (CH₃CH=CHCH₂Ar), 55.82 (OCH₃), 64.26

(OCH₂CH₃), 70.70, 111.35, 113.08, 114.37, 126.11, 130.16,

130.26, 132.40, 139.92, 146.75, 148.51; EI-MS (70 eV) m/z

(rel. intensity, %) 262 (M⁺, 72), 244 (47), 201 (44), 191 (53),

189 (42), 177 (49), 175 (69), 174 (51), 161 (46), 145 (63), 131

(58), 128 (47), 115 (75); HRMS: calcd. for C₁₆H₂₂O₃:

262.1569. Found: 262.1567.

1

137.71, 140.24, 143.41, 145.84, 152.38; H-NMR (CDCl₃,

minor diastereomer 400 MHz) d 1.36 (d, J = 7.2 Hz, 3H,

CH₂=CH(CH₃)CHAr), 1.94 (br s, 1H, OH), 3.86 (s, 3H,

OCH₃), 4.11 (m, 1H, CH₂=CH(CH₃)CHAr), 4.97 (ddd, J =

10.3 Hz, 2.4 Hz, 1.2 Hz, 1H, CH₂=CH(CH₃)CH), 4.99 (s, 2H,

OCH₂C₆H₅), 5.01 (ddd, J = 17.3 Hz, 2.4 Hz, 1.2 Hz, 1H,

CH₂=CH(CH₃)CH), 5.19 (ddd, J = 10.6 Hz, 1.2 Hz, 1.2 Hz,

1H, CH₂=CHCH), 5.31 (ddd, J = 17.2 Hz, 1.2 Hz, 1.2 Hz, 1H,

CH₂=CHCH), 5.51 (br s, 1H, CH₂=CHCH), 6.03 (ddd, J =

17.2 Hz, 10.6 Hz, 5.6 Hz, 1H, CH₂=CHCH), 6.15 (ddd, J =

17.3 Hz, 10.3 Hz, 4.8 Hz, 1H, CH₂=CHCH₃CHAr), 6.84, 7.17

(each d, J = 8.8 Hz, 1H, ArH), 7.31-7.47 (m, 5H, OCH₂C₆H₅);

¹³C-NMR (CDCl₃, minor diastereomer 100 MHz) d 19.80

(CH₂=CH(CH₃)CH), 35.00 (CH₂=CH(CH₃)CH), 55.67 (OCH₃),

70.70, 74.46 (OCH₂C₆H₅), 110.83, 113.05, 114.38, 123.97,

127.71, 127.92, 128.31, 133.78, 133.90, 137.81, 140.29,

143.59, 146.00, 152.48; EI-MS (70 eV) m/z (rel. intensity, %)

324 (M⁺, 0.4), 233 (8), 191 (3), 173 (3), 161 (2), 159 (3), 131

(5), 151 (7), 103 (3), 92 (9), 91 (100); HRMS: calcd. for

C₂₁H₂₄O₃: 324.1725. Found: 324.1720.

1-(5-Benzyloxy-2-butenyl-4-methoxyphenyl)-2-propen-1-

ols (8c)

Pure 8c (1.49 g, 92%) was obtained as pale yellow liq-

1

uid, R_f= 0.60 (EA/n-hexane = 1/3); H-NMR (CDCl₃, 400

MHz) d 1.66 (dd, J = 6.4 Hz, 1.3 Hz, 3H, CH₃CH=CH-

CH₂Ar), 1.84 (br s, 1H, OH), 3.32 (d, J = 6.0 Hz, 2H,

CH₃CH=CH-CH₂Ar), 3.86 (s, 3H, OCH₃), 5.07 (s, 2H,

OCH₂C₆H₅), 5.14 (ddd, J = 10.4 Hz, 1.6 Hz, 1.2 Hz, 1H,

CH₂=CHCHOH), 5.27 (ddd, J = 17.2 Hz, 1.6 Hz, 1.2 Hz, 1H,

CH₂=CHCHOH), 5.33 (br s, 1H, CH₂=CHCHOH), 5.42 (dq,

J = 13.2 Hz, 6.2 Hz, 1H, CH₃CH=CHCH₂Ar), 5.56 (dtq, J =

13.2 Hz, 6.0 Hz, 1.3 Hz, 1H, CH₃CH=CHCH₂Ar), 5.94 (ddd,

J =17.2 Hz, 10.4 Hz, 4.4 Hz, 1H, CH₂=CHCHOH), 6.68, 7.00

(each s, 1H, ArH), 7.27-7.43 (m, 5H, OCH₂C₆H₅); ¹³C-NMR

(CDCl₃, 100 MHz) d 17.81 (CH₃), 35.52 (CH₃CH=CHCH₂),

56.08 (OCH₃), 70.67, 71.16 (OCH₂C₆H₅), 112.87, 113.54,

114.55, 126.78, 127.54, 127.75, 128.40, 130.18, 131.09,

132.44, 137.20, 139.80, 146.70, 149.07; EI-MS (70 eV) m/z

(rel. intensity, %) 324 (M⁺, 2), 215 (12), 187 (3), 183 (6), 157

1-(2-Butenyl-4,5-dimethoxyphenyl)-2-propen-1-ols (8a)

Pure 8a (1.03 g, 83%) was obtained as pale yellow liq-

1

uid, R_f= 0.40 (EA/n-hexane = 1/3); H NMR (CDCl₃, 400

MHz) d 1.66 (dd, J = 6.4 Hz, 1.3 Hz, 3H, CH₃CH=CH-

CH₂Ar), 2.31 (br s, 1H, OH), 3.32 (d, J = 6.0 Hz, 2H,

CH₃CH=CHCH₂Ar), 3.84, 3.85 (each s, 3H, OCH₃), 5.18

(ddd, J = 10.4 Hz, 1.6 Hz, 1.2 Hz, 1H, CH₂=CHCHOH), 5.31

(ddd, J = 17.2 Hz, 1.6 Hz, 1.2 Hz, 1H, CH₂=CHCHOH), 5.40

(br s, 1H, CH₂=CHCHOH), 5.42 (dq, J = 13.2 Hz, 6.4 Hz, 1H,

CH₃CH=CHCH₂Ar), 5.56 (dtq, J = 13.2 Hz, 6.0 Hz, 1.3 Hz,

1H, CH₃CH=CHCH₂Ar), 6.01 (ddd, J = 17.2 Hz, 10.4 Hz, 4.4

Hz, 1H, CH₂=CHCHOH), 6.65, 6.96 (each s, 1H, ArH); ¹³C-

NMR (CDCl₃, 100 MHz) d 17.68 (CH₃), 35.05 (CH₃CH=CH-

CH₂Ar), 55.71, 55.71 (each, OCH₃), 70.67, 109.68, 112.75,

Syntheses of Substituted Naphthalenes and Naphthols

J. Chin. Chem. Soc., Vol. 51, No. 3, 2004 599

(3), 155 (14), 145 (3), 131 (10), 129 (8), 117 (5), 115 (9), 105

(4), 103 (6), 92 (7), 91(100); HRMS: calcd. for C₂₁H₂₄O₃:

324.1725. Found: 324.1726.

¹H-NMR (CDCl₃, 600 MHz) d 4.05 (s, 3H, OCH₃), 5.27 (s,

2H, OCH₂C₆H₅), 7.37, 7.68 (each d, J = 9.0 Hz, 1H, 3-H and

4-H), 7.42, 7.52 (each t, J = 7.5 Hz, 1H, 6-H and 7-H),

7.43-7.43 (m, 5H, OCH₂C₆H₅), 7.50, 8.24 (each d, J = 8.5 Hz,

1H, 5-H and 8-H); ¹³C-NMR (CDCl₃, 100 MHz) d 56.75

(OCH₃), 75.10 (OCH₂C₆H₅), 115.16, 121.43, 123.94, 124.17,

125.95, 127.48, 127.78, 128.06, 128.28, 129.21, 129.57,

137.83, 141.76, 148.33; EI-MS (70 eV) m/z (rel. intensity, %)

264 (M⁺, 100), 231 (37), 203 (33), 202 (35), 143 (16), 116

(14), 115 (42), 105 (28), 101 (32), 91(23); HRMS: calcd. for

C₁₈H₁₆O₂: 264.1150. Found: 264.1158.

General procedure for the preparation of naphthalenes

9a-f and 10a-c

Compounds 7a-f or 8a-c (1 mmol) dissolved in anhy-

drous CH₂Cl₂(20 mL), and mixed with Grubbs catalyst (5%

mol). The mixture was stirred for 2 h at ambient temperature

under dry argon. Finally, the solvent was removed under re-

duced pressure, and the residue was subjected to a silica gel

column (3:1 hexane/MTBE) or distilled under vacuum to

give 9a-f and 10a-c, respectively.

1,2-Dimethoxy-8-methylnaphthalene (9d)^18b,c

Pure 9d (0.18 g, 89%) was obtained as colorless liquid,

bp 95-96 °C (3 mmHg); R_f= 0.83 (EA/n-hexane = 1/3);

¹H-NMR (CDCl₃, 600 MHz) d 2.93 (s, 3H, CH₃), 3.93, 4.00

(each s, 3H, 2-OCH₃and 1-OCH₃), 7.22, 7.23 (each d, J = 4.7

Hz, 1H, 7-H and 5-H), 7.29, 7.60 (each d, J = 9.0 Hz, 1H, 3-H

and 4-H), 7.62 (t, J = 4.7 Hz, 1H, 6-H); ¹³C-NMR (CDCl₃,

100 MHz) d 23.47 (CH₃), 56.58 (OCH₃), 60.92 (OCH₃),

114.39, 123.55, 124.90, 126.36, 128.25, 128.95, 130.77,

133.18, 145.20, 149.66; EI-MS (70 eV) m/z (rel. intensity, %)

202 (M⁺, 96), 187 (100), 172 (26), 159 (81), 144 (59), 141

(24), 131 (17), 128 (16), 116 (27), 115 (58); HRMS: calcd. for

C₁₃H₁₄O₂: 202.0994. Found: 202.0992.

1,2-Dimethoxynaphthalene (9a)^18a

Pure 9a (0.16 g, 86%) was obtained as colorless liquid,

bp 80-81 °C (3 mmHg); R_f= 0.74 (EA/n-hexane = 1/3);

¹H-NMR (CDCl₃, 500 MHz) d 4.03, 4.10 (each s, 3H,

2-OCH₃and 1-OCH₃), 7.31, 7.60 (each d, J = 9.0 Hz, 1H, 3-H

and 4-H), 7.36, 7.48 (each t, J = 7.5 Hz, 1H, 6-H and 7-H),

7.81, 8.13 (each d, J = 8.5 Hz, 1H, 5-H and 8-H); ¹³C NMR

(CDCl₃, 100 MHz) d 56.37 (OCH₃), 60.64 (OCH₃), 114.92,

120.97, 123.73, 123.87, 125.78, 127.39, 128.77, 129.42,

142.59, 148.01; EI-MS (70 eV) m/z (rel. intensity, %) 188

(M⁺, 100), 173 (73), 145 (58), 130 (29), 127 (64), 117 (31),

115 (32), 102 (31); HRMS: calcd. for C₁₂H₁₂O₂: 188.0837.

Found: 188.0839.

1-Ethoxy-2-methoxy-8-methylnaphthalene (9e)

Pure 9e (0.19 g, 89%) was obtained as colorless liquid,

bp 100-101 °C (3 mmHg); R_f= 0.87 (EA/n-hexane = 1/3);

¹H-NMR (CDCl₃, 600 MHz) d 1.45 (t, J = 7.2 Hz, 3H,

OCH₂CH₃), 2.90 (s, 3H, CH₃), 3.92 (s, 3H, OCH₃), 4.06 (q, J

= 7.2 Hz, 2H, OCH₂CH₃), 7.16, 7.18 (each d, J = 4.8 Hz, 1H,

7-H and 5-H), 7.21, 7.53 (each d, J = 9.0 Hz, 1H, 3-H and

4-H), 7.56 (t, J = 4.8 Hz, 1H, 6-H); ¹³C-NMR (CDCl₃, 100

MHz) d 15.37 (OCH₂CH₃), 23.76 (CH₃), 56.71 (OCH₃),

69.25 (OCH₂CH₃), 114.49, 123.49, 124.84, 126.42, 126.65,

128.95, 130.88, 133.35, 144.15, 149.81; EI-MS (70 eV) m/z

(rel. intensity, %) 216 (M⁺, 79), 188 (34), 187 (100), 173 (52),

172 (20), 159 (54), 145 (27), 144 (37), 116 (20), 115 (46);

HRMS: calcd. for C₁₄H₁₆O₂: 216.1150. Found: 216.1153.

1-Ethoxy-2-methoxynaphthalene (9b)

Pure 9b (0.19 g, 89%) was obtained as colorless liquid,

bp 90-91 °C (3 mmHg); R_f= 0.81 (EA/n-hexane = 1/3);

¹H-NMR (CDCl₃, 600 MHz) d 1.31 (t, J = 6.8 Hz, 3H,

OCH₂CH₃), 3.72 (s, 3H, OCH₃), 4.03 (q, J = 6.8 Hz, 2H,

OCH₂CH₃), 7.03, 7.35 (each d, J = 9.0 Hz, 1H, 3-H and 4-H),

7.15, 7.28 (each t, J = 7.5 Hz, 1H, 6-H and 7-H), 7.57, 8.02

(each d, J = 8.5 Hz, 1H, 5-H and 8-H); ¹³C-NMR (CDCl₃, 100

MHz) d 15.64 (OCH₂CH₃), 56.59 (OCH₃), 68.96 (OCH₂CH₃),

115.13, 121.39, 123.81, 123.85, 125.76, 127.42, 129.41,

129.54, 141.83, 148.25; EI-MS (70 eV) m/z (rel. intensity, %)

202 (M⁺, 100), 174 (58), 173 (77), 159 (91), 145 (58), 131

(39), 130 (23), 127 (60), 117 (29), 115 (40), 103 (18), 102

(38); HRMS: calcd. for C₁₃H₁₄O₂: 202.0994 Found:

202.0993.

1-Benzyloxy-2-methoxy-8-methylnaphthalene (9f)

Pure 9f (0.22 g, 80%) was obtained as colorless crys-

tals, mp 67-68 °C, bp 120-121 °C (3 mmHg); R_f= 0.88

(EA/n-hexane = 1/3); ¹H-NMR (CDCl₃, 600 MHz) d 2.89 (s,

3H, CH₃), 3.99 (s, 3H, OCH₃), 5.07 (s, 2H, OCH₂C₆H₅), 7.20,

7.21 (each d, J = 5.2 Hz, 1H, 7-H and 5-H), 7.31, 7.62 (each d,

1-Benzyloxy-2-methoxynaphthalene (9c)

Pure 9c (0.23 g, 83%) was obtained as colorless liquid,

bp 145-146 °C (3 mmHg); R_f= 0.86 (EA/n-hexane = 1/3);

600 J. Chin. Chem. Soc., Vol. 51, No. 3, 2004

Huang et al.

J = 9.0 Hz, 1H, 3-H and 4-H), 7.61 (t, J = 5.2 Hz, 1H, 6-H),

7.35-7.57 (m, 5H, OCH₂C₆H₅); ¹³C-NMR (CDCl₃, 100 MHz)

d 24.05 (CH₃), 56.85 (OCH₃), 75.56 (OCH₂C₆H₅), 114.61,

123.64, 125.26, 126.49, 127.71, 127.93, 128.36, 128.65,

129.10, 130.92, 133.35, 137.92, 144.12, 149.81; EI-MS (70

eV) m/z (rel. intensity, %) 278 (M⁺, 100), 263 (23), 245 (21),

235 (12), 202 (28), 145 (25), 129 (14), 115 (22), 91 (20);

HRMS: calcd. for C₁₉H₁₈O₂: 278.1307. Found: 278.1307.

Found: 264.1142.

General procedure for preparing 11a-f and 12a-c

Each compound of 7a-f and 8a-c (3 mmol) was dis-

solved in anhydrous CH₂Cl₂(20 mL), added to oxidizing

agent PCC (3.5 mmol) or dMP (3.5 mmol), and stirred for 1 h

at room temperature. After the end of reaction, the reaction

mixture was extracted with ethyl acetate (15 mL ´ 5). The ex-

tracted solution was washed with brine (10 mL ´ 2), dried

with anhydrous MgSO₄, and filtered. The filtrate was concen-

trated under vacuum, and the given residue was subjected to

chromatographic column (silica gel, n-hexane/EA = 5/1) to

furnish the pure 11a-f and 12a-c.

2,3-Dimethoxynaphthalene (10a)^18d

Pure 10a (0.15 g, 82%) was obtained as colorless crys-

tals, mp 67-68 °C; R_f= 0.72 (EA/n-hexane = 1/3); ¹H-NMR

(CDCl₃, 600 MHz) d 4.00 (s, 6H, 2-OCH₃and 3-OCH₃), 7.13

(s, 2H, 1-H and 4-H), 7.35 (t, J = 7.5 Hz, 2H, 6-H and 7-H),

7.70 (d, J = 8.5 Hz, 2H, 5-H and 8-H); ¹³C-NMR (CDCl₃, 100

MHz) d 55.82 (2-OCH₃and 3-OCH₃), 106.31, 124.17,

126.28, 129.18, 149.45 (2-C and 3-C); EI-MS (70 eV) m/z

(rel. intensity, %) 188 (M⁺, 100), 173 (20), 145 (40), 130 (10),

127 (22), 117 (26), 115 (47), 102 (34); HRMS: calcd. for

C₁₂H₁₂O₂: 188.0837. Found: 188.0831.

1-(2-Ally-3,4-dimethoxy)phenyl vinyl ketone (11a)

Pure 11a (0.45 g, 65%) was obtained as colorless liquid,

R_f= 0.61 (EA/n-hexane = 1/4); ¹H-NMR (CDCl₃, 200 MHz)

d 3.65 (ddd, J = 6.0 Hz, 1.6 Hz, 1.6 Hz, 2H, ArCH₂CH=CH₂),

3.82, 3.91 (each s, 3H, OCH₃), 4.97 (ddt, J = 17.4 Hz, 2.0 Hz,

1.6 Hz, 1H, CH₂=CHCH₂Ar), 5.00 (ddt, J = 10.4 Hz, 2.0 Hz,

1.6 Hz, 1H, CH₂=CHCH₂Ar), 5.92 (dd, J_cis-gem= 10.5 Hz, 1.5

Hz, 1H, ArCOCH=CH₂), 5.94 (ddt, J = 17.4 Hz, 10.4 Hz, 6.0

Hz, 1H, CH₂=CHCH₂Ar), 6.15 (dd, J_trans-gem= 17.3 Hz, 1.5

Hz, 1H, ArCOCH=CH₂), 6.79 (dd, J_trans-cis= 17.3 Hz, 10.5

Hz, 1H, ArCOCH=CH₂), 6.82, 7.28 (each d, J = 8.5 Hz, 1H,

H-5 and H-6); ¹³C-NMR (CDCl₃, 50 MHz), d 30.45, 55.66,

60.75, 109.01, 115.09, 125.86, 130.30, 131.39, 134.32,

136.50, 137.29, 147.79, 155.05, 194.72; EI-MS (70 eV) m/z

(rel. intensity, %) 232 (M⁺, 36), 217 (43), 201 (20), 191 (100),

190 (24), 189 (26), 175 (15), 174 (22), 131 (15), 115 (16);

HRMS: calcd. for C₁₄H₁₆O₃: 232.1099. Found: 232.1098.

2-Ethoxy-3-methoxynaphthalene (10b)

Pure 10b (0.17 g, 84%) was obtained as colorless crys-

tals, mp 77-78 °C; R_f= 0.74 (EA/n-hexane = 1/3); ¹H-NMR

(CDCl₃, 600 MHz) d 1.56 (t, J = 7.2 Hz, 3H, OCH₂CH₃), 4.00

(s, 3H, OCH₃), 4.23 (q, J = 7.2 Hz, 2H, OCH₂CH₃), 7.13 (s,

2H, 1-H and 4-H), 7.33, 7.35 (each t, J = 7.5 Hz, 1H, 6-H and

7-H), 7.68 (d, J = 8.5 Hz, 2H, 5-H and 8-H); ¹³C-NMR

(CDCl₃, 100 MHz) d 14.61 (OCH₂CH₃), 55.80 (OCH₃), 64.09

(OCH₂CH₃), 106.36, 107.27, 124.04, 127.30, 127.90, 126.20,

129.07, 129.19, 148.72, 149.65; EI-MS (70 eV) m/z (rel. in-

tensity, %) 202 (M⁺, 79), 174 (100), 159 (58), 131 (91), 115

(31), 102 (33); HRMS: calcd for C₁₃H₁₄O₂: 202.0994. Found:

202.0992.

3-(2-Allyl-3,4-dimethoxyphenyl)-1-propenal (11a-un)

Pure 11a-un (0.26 g, 33%) was obtained as pale yellow

1

crystals, mp 35-36 °C, R_f= 0.66 (EA/n-hexane = 1/4); H-

2-Benzyloxy-3-methoxynaphthalene (10c)^18e

NMR (CDCl₃, 200 MHz) d 3.63 (dt, J = 5.6 Hz, 1.8 Hz, 2H,

ArCH₂CH=CH₂), 3.82, 3.92 (each s, 3H, OCH₃), 4.89 (ddt, J

= 17.4 Hz, 1.8 Hz, 1.8 Hz, 1H, ArCH₂CH=CH₂), 5.08 (ddt, J

= 10.2 Hz, 1.8 Hz, 1.8 Hz, 1H, ArCH₂CH=CH₂), 5.99 (ddt, J

= 17.4 Hz, 10.2 Hz, 5.6 Hz, 1H, ArCH₂CH=CH₂), 6.59 (dd, J

= 15.8 Hz, 8.0 Hz, 1H, ArCH=CHCHO), 6.88, 7.44 (each d, J

= 8.8 Hz, 1H, ArH), 7.65 (d, J = 15.8 Hz, 1H, ArCH=CHCHO),

9.65 (d, J = 8.0 Hz, 1H, CHO); ¹³C-NMR (CDCl₃, 50 MHz), d

29.81, 55.74, 60.96, 110.67, 115.98, 123.39, 126.45, 128.15,

133.81, 136.39, 147.42, 150.35, 154.99, 193.76 (C=O);

EI-MS (70 eV) m/z (rel. intensity, %) 232 (M⁺, 29), 201 (15),

191 (100), 189 (23), 188 (21), 176 (23), 174 (14), 172 (15),

Pure 10c (0.23 g, 89%) was obtained as colorless crys-

1

tals, mp 137-138 °C; R_f= 0.77 (EA/n-hexane = 1/3); H-

NMR (CDCl₃, 600 MHz) d 4.00 (s, 3H, OCH₃), 5.27 (s, 2H,

OCH₂C₆H₅), 7.14, 7.16 (each s, 1H, 1-H and 4-H), 7.32, 7.33

(each t, J = 7.5 Hz, 1H, 6-H and 7-H), 7.32-7.50 (m, 5H,

OCH₂C₆H₅), 7.62, 7.68 (each d, J = 8.5 Hz, 1H, 5-H and 8-H);

¹³C-NMR (CDCl₃, 100 MHz) d 55.88 (OCH₃), 7.32 (OCH₂C₆H₅),

106.63, 108.89, 124.07, 124.26, 126.24, 126.34, 127.30,

127.90, 128.59, 129.06, 129.36, 136.81, 148.58, 149.92;

EI-MS (70 eV) m/z (rel. intensity, %) 264 (M⁺, 15), 145(3),

115(8), 102(9), 91(100); HRMS: calcd. for C₁₈H₁₆O₂: 264.1150.

Syntheses of Substituted Naphthalenes and Naphthols

158 (21), 115 (25).

J. Chin. Chem. Soc., Vol. 51, No. 3, 2004 601

(m, 1H, CH₂=CHCH(CH₃)Ar), 3.90, 3.94 (each s, 3H,

OCH₃), 4.96 (ddd, J = 10.4 Hz, 2.4 Hz, 1.2 Hz, 1H,

CH₂=CHCH(CH₃)Ar), 4.98 (ddd, J = 17.4 Hz, 2.4 Hz, 1.2 Hz,

1H, CH₂=CHCH(CH₃)Ar), 5.98 (dd, J = 10.6 Hz, 1.2 Hz, 1H,

CH₂=CHCOAr), 6.07 (dd, J = 17.5 Hz, 1.2 Hz, 1H,

CH₂=CHCOAr), 6.16 (ddd, J = 17.4 Hz, 10.4 Hz, 6.4 Hz, 1H,

CH₂=CHCH(CH₃)Ar), 6.68 (dd, J = 17.5 Hz, 10.6 Hz, 1H,

CH₂=CHCOAr), 6.79, 7.04 (each d, J = 8.5 Hz, 1H, ArH);

¹³C-NMR (CDCl₃, 75 MHz) d 19.52, 38.10, 55.60, 60.52,

109.38, 113.30, 124.18, 131.33, 132.03, 136.66, 137.65,

142.59, 148.09, 154.65, 197.10; EI-MS (70 eV) m/z (rel. in-

tensity, %) 246 (M⁺, 20), 231 (100), 218 (38), 216 (27), 205

(95), 204 (26), 203 (75), 201 (21), 189 (26), 188 (28), 187

(28), 175 (26), 115 (21); HRMS: calcd. for C₁₅H₁₈O₃:

246.1256. Found: 246.1255.

1-(2-Allyl-3-ethoxy-4-methoxy)phenyl vinyl ketone (11b)

Pure 11b (0.48 g, 65%) was obtained as colorless liq-

1

uid, R_f= 0.59 (EA/n-hexane = 1/4); H-NMR (CDCl₃, 300

MHz) d 1.44 (t, J = 7.2 Hz, 3H, OCH₂CH₃), 3.65 (ddd, J = 5.8

Hz, 1.6 Hz, 1.6 Hz, 2H, ArCH₂CH=CH₂), 3.94 (s, 3H, OCH₃),

4.07 (q, J = 7.2 Hz, 2H, OCH₂CH₃), 4.99 (ddt, J = 17.4 Hz, 2.0

Hz, 1.6 Hz, 1H, CH₂=CHCH₂Ar), 5.09 (ddt, J = 10.4 Hz, 2.0

Hz, 1.6 Hz, 1H, CH₂=CHCH₂Ar), 5.97 (dd, J_cis-gem= 10.3 Hz,

1.4 Hz, 1H, ArCOCH=CH₂), 5.96 (ddt, J = 17.4 Hz, 10.4 Hz,

5.8 Hz, 1H, CH₂=CHCH₂Ar), 6.20 (dd, J_trans-gem= 17.3 Hz,

1.4 Hz, 1H, ArCOCH=CH₂), 6.85 (dd, J_trans-cis= 17.3 Hz, 10.3

Hz, 1H, ArCOCH=CH₂), 6.86, 7.32 (each d, J = 8.5 Hz, 1H,

H-5 and H-6); ¹³C-NMR (CDCl₃, 75 MHz), d 15.55, 30.53,

55.74, 68.78, 108.84, 114.94, 125.72, 128.07, 131.31,

134.38, 136.48, 145.33, 146.93, 155.13, 194.77; EI-MS (70

eV) m/z (rel. intensity, %) 246 (M⁺, 43), 231 (50), 217 (33),

205 (100), 203 (31), 190 (25), 189 (32), 185 (20), 177 (22),

175 (37), 159 (27), 157 (25), 131 (24), 91 (24); HRMS: calcd.

for C₁₅H₁₈O₃: 246.1256. Found: 246.1257.

1-[3-Ethoxy-4-methoxyl-2-(1-methyallyl)]phenyl vinyl

ketone (11e)

Pure 11e (0.49 g, 63%) was obtained as colorless liquid,

R_f= 0.61 (EA/n-hexane = 1/4); ¹H-NMR (CDCl₃, 300 MHz)

d 1.45 (d, J = 7.2 Hz, 3H, CH₂=CHCH(CH₃)Ar), 1.46 (t, J =

7.2 Hz, 3H, OCH₂CH₃), 3.89 (m, 1H, CH₂=CHCH(CH₃)Ar),

3.90 (s, 3H, OCH₃), 4.13 (q, J = 7.2 Hz, 2H, OCH₂CH₃), 5.00

(ddd, J = 10.4 Hz, 2.4 Hz, 1.2 Hz, 1H, CH₂=CHCH(CH₃)Ar),

5.05 (ddd, J = 16.4 Hz, 2.4 Hz, 1.2 Hz, 1H, CH₂=CHCH(CH₃)Ar),

6.04 (dd, J = 10.6 Hz, 1.2 Hz, 1H, CH₂=CHCOAr), 6.10 (dd, J

= 17.5 Hz, 1.2 Hz, 1H, CH₂=CHCOAr), 6.22 (ddd, J = 16.4

Hz, 10.4 Hz, 5.8 Hz, 1H, CH₂=CHCH(CH₃)Ar), 6.73 (dd, J =

17.5 Hz, 10.6 Hz, 1H, CH₂=CHCOAr), 6.84, 7.08 (each d, J =

8.5 Hz, 1H, ArH); ¹³C-NMR (CDCl₃, 75 MHz) d 15.33,

19.41, 37.81, 55.53, 68.09, 109.19, 113.20, 124.04, 131.21,

132.07, 137.67, 138.62, 142.52, 147.03, 154.67, 197.17;

EI-MS (70 eV) m/z (rel. intensity, %) 260 (M⁺, 28), 245 (89),

232 (32), 219 (100), 217 (29), 216 (21), 204 (28), 203 (77),

189 (41), 187 (23), 175 (28), 173 (22), 115 (29); HRMS:

calcd. for C₁₆H₂₀O₃: 260.1412. Found: 260.1414.

1-(2-Allyl-3-benzyloxy-4-methoxy)phenyl vinyl ketone

(11c)

Pure 11c (0.55 g, 60%) was obtained as colorless liquid,

R_f= 0.56 (EA/n-hexane = 1/4); ¹H-NMR (CDCl₃, 200 MHz)

d 3.65 (ddd, J = 5.8 Hz, 1.6 Hz, 1.6 Hz, 2H, CH₂CH=CH₂),

3.91 (s, 3H, OCH₃), 4.90 (ddt, J = 17.4 Hz, 2.0 Hz, 1.6 Hz,

1H, CH₂=CHCH₂Ar), 4.95 (ddt, J = 10.4 Hz, 2.0 Hz, 1.6 Hz,

1H, CH₂=CHCH₂Ar), 4.99 (s, 2H, OCH₂Ph), 5.91 (dd, J_cis-gem

= 10.5 Hz, 1.5 Hz, 1H, ArCOCH=CH₂), 5.92 (ddt, J = 17.4

Hz, 10.4 Hz, 5.8 Hz, 1H, CH₂=CHCH₂Ar), 6.14 (dd, J_trans-gem

= 17.4 Hz, 1.5 Hz, 1H, ArCOCH=CH₂), 6.78 (dd, J_trans-cis

=

17.4 Hz, 10.5 Hz, 1H, ArCOCH=CH₂), 6.84, 7.30 (each d, J =

8.5 Hz, 1H, H-5 and H-6), 7.32-7.48 (m, 5H, OCH₂C₆H₅);

¹³C-NMR (CDCl₃, 50 MHz), d 30.61, 55.71, 74.64, 109.06,

115.20, 126.02, 127.86, 127.92, 128.33, 130.32, 131.48,

134.59, 136.53, 137.22, 137.62, 146.59, 155.13, 194.79;

EI-MS (70 eV) m/z (rel. intensity, %) 308 (M⁺, 1), 219 (1),

218 (7), 217 (47), 203 (10), 189 (4), 185 (7), 175 (3), 157 (3),

115 (3), 92 (8), 91 (100); HRMS: calcd. for C₂₀H₂₀O₃:

308.1412. Found: 308.1412.

1-[3-Benzyloxy-4-methoxyl-2-(1-methyallyl)]phenyl vinyl

ketone (11f)

Pure 11f (0.58 g, 60%) was obtained as colorless liquid,

R_f= 0.57 (EA/n-hexane = 1/4); ¹H-NMR (CDCl₃, 300 MHz)

d 1.50 (d, J = 7.2 Hz, 3H, CH₂=CHCH(CH₃)Ar), 3.96 (m, 1H,

CH₂=CHCH(CH₃)Ar), 3.98 (s, 3H, OCH₃), 5.03 (ddd, J =

10.4 Hz, 2.4 Hz, 1.2 Hz, 1H, CH₂=CHCH(CH₃)Ar), 5.06

(ddd, J = 16.4 Hz, 2.4 Hz, 1.2 Hz, 1H, CH₂=CHCH(CH₃)Ar),

5.15 (s, 2H, OCH₂C₆H₅), 6.09 (dd, J = 10.6 Hz, 1.2 Hz, 1H,

CH₂=CHCOAr), 6.15 (dd, J = 17.5 Hz, 1.2 Hz, 1H,

CH₂=CHCOAr), 6.22 (ddd, J = 16.4 Hz, 10.4 Hz, 5.8 Hz, 1H,

1-[3,4-Dimethoxyl-2-(1-methyallyl)]phenyl vinyl ketone

(11d)

Pure 11d (0.43 g, 58%) was obtained as colorless liq-

1

uid, R_f= 0.59 (EA/n-hexane = 1/4); H-NMR (CDCl₃, 300

MHz) d 1.48 (d, J = 6.8 Hz, 3H, CH₂=CHCH(CH₃)Ar), 3.87

602 J. Chin. Chem. Soc., Vol. 51, No. 3, 2004

Huang et al.

CH₂=CHCH(CH₃)Ar), 6.77 (dd, J = 17.5 Hz, 10.6 Hz, 1H,

CH₂=CHCOAr), 6.92, 7.15 (each d, J = 8.5 Hz, 1H, ArH),

7.35-7.58 (m, 5H, OCH₂C₆H₅); ¹³C-NMR (CDCl₃, 75 MHz) d

19.57, 37.82, 55.66, 73.88, 109.37, 113.63, 124.45, 127.83,

128.08, 128.27, 129.33, 131.38, 132.20, 137.83, 139.01,

142.52, 146.72, 154.62, 197.24; EI-MS (70 eV) m/z (rel. in-

tensity, %) 322 (M⁺, 2), 231 (11), 213 (5), 203 (5), 115 (6), 92

(9), 91 (100); HRMS: calcd. for C₂₁H₂₂O₃: 322.1569. Found:

322.1567.

1-[5-Benzyloxy-(2-butenyl)-4-methoxy]phenyl vinyl

ketone (12c)

Pure 12c (0.66 g, 69%) was obtained as colorless liquid,

R_f= 0.41 (EA/n-hexane = 1/4); ¹H-NMR (CDCl₃, 300 MHz)

d 1.65 (dd, J = 5.7 Hz, 1.2 Hz, 3H, CH₃CH=CHCH₂Ar), 3.44

(d, J = 6.2 Hz, 2H, CH₃CH=CHCH₂Ar), 3.93 (s, 3H, OCH₃),

5.13 (s, 2H, OCH₂C₆H₅), 5.46 (dq, J = 13.2 Hz, 5.7 Hz, 1H,

CH₃CH=CHCH₂Ar), 5.49 (dtq, J = 13.2 Hz, 6.2 Hz, 1.2 Hz,

1H, CH₃CH=CHCH₂Ar), 5.84 (dd, J = 10.4 Hz, 1.3 Hz, 1H,

ArCOCH₂=CH₂), 6.00 (dd, J = 17.5 Hz, 1.3 Hz, 1H,

ArCOCH₂=CH₂), 6.67 (dd, J = 17.5 Hz, 10.4 Hz, 1H,

ArCOCH=CH₂), 6.78, 7.02 (each s, 1H, H-3 and H-6), 7.35-

7.46 (m, 5H, OCH₂C₆H₅); ¹³C-NMR (CDCl₃, 75 MHz), d

17.85, 36.25, 55.96, 71.36, 113.75, 115.63, 126.47, 127.40,

127.95, 128.56, 128.88, 129.50, 130.22, 135.57, 136.49,

136.81, 145.23, 151.89, 194.83; EI-MS (70 eV) m/z (rel. in-

tensity, %) 322 (M⁺, 2), 232 (2), 231 (11), 213 (5), 203 (5),

189 (3), 181 (2), 175 (3), 115 (6), 92 (9), 91 (100); HRMS:

calcd. for C₂₁H₂₂O₃: 322.1569. Found: 322.1569.

1-[(2-Butenyl)-4,5-dimethoxy]phenyl vinyl ketone (12a)

Pure 12a (0.51 g, 69%) was obtained as colorless liq-

1

uid, R_f= 0.42 (EA/n-hexane = 1/4); H-NMR (CDCl₃, 200

MHz) d 1.64 (dd, J = 5.7 Hz, 1.3 Hz, 3H, CH₃CH=CH-

CH₂Ar), 3.46 (d, J = 6.2 Hz, 2H, CH₃CH=CHCH₂Ar), 3.88,

3.92 (each s, 3H, OCH₃), 5.42 (dq, J = 13.2 Hz, 5.7 Hz, 1H,

CH₃CH=CHCH₂Ar), 5.56 (dtq, J = 13.2 Hz, 6.2 Hz, 1.3 Hz,

1H, CH₃CH=CHCH₂Ar), 5.93 (dd, J = 10.4 Hz, 1.3 Hz, 1H,

ArCOCH=CH₂), 6.18 (dd, J = 17.5 Hz, 1.3 Hz, 1H,

ArCOCH=CH₂), 6.76, 7.00 (each s, 1H, H-3 and H-6), 6.81

(dd, J = 17.5 Hz, 10.4 Hz, 1H, ArCOCH=CH₂); ¹³C-NMR

(CDCl₃, 50 MHz), d 17.77, 36.19, 55.84, 56.03, 112.14,

113.23, 126.42, 129.90, 129.96, 130.07, 134.63, 136.54,

146.45, 151.06, 194.88; EI-MS (70 eV) m/z (rel. intensity, %)

246 (M⁺, 82), 231 (76), 217 (95), 205 (45), 204 (60), 191

(100), 161 (41), 145 (32), 133 (34), 131 (40), 128 (34), 115

(39); HRMS: calcd. for C₁₅H₁₈O₃: 246.1256. Found: 246.1256.

General procedure for the preparation of naphthols

15a-f and 16a-c

Compound 11a-f or 12a-c (1 mmol) was dissolved in

anhydrous CH₂Cl₂(20 mL) and then mixed with Grubbs cata-

lyst (5% mol). Under dry argon, the mixture, stirred at ambi-

ent temperature for 12 h, was concentrated under reduced

pressure. The resulting residue was subjected to a silica gel

column (3:1 hexane/MTBE) or distilled under vacuum to

give 15a-f and 16a-c, respectively.

1-[(2-Butenyl)-5-ethoxy-4-methoxy]phenyl vinyl ketone

(12b)

Pure 12b (0.56 g, 72%) was obtained as colorless liq-

5,6-Dimethoxy-1-naphthol (15a)¹⁹

1

uid, R_f= 0.40 (EA/n-hexane = 1/4); H-NMR (CDCl₃, 300

Pure 15a (0.13 g, 62%) was obtained as colorless crys-

tals, mp 149-150 °C; R_f= 0.34 (EA/n-hexane = 1/4);

¹H-NMR (CDCl₃, 400 MHz) d 3.98, 3.99 (each s, 3H, OCH₃),

5.45 (br s, 1H, OH), 6.68, 7.26 (each d, J = 7.6 Hz, 1H, H-2

and H-4), 7.28 (t, J = 7.6 Hz, 1H, H-3), 7.68, 7.96 (each d, J =

9.2 Hz, 1H, H-7 and H-8); ¹³C-NMR (CDCl₃, 100 MHz), d

55.76, 60.13, 105.78, 112.93, 114.55, 117.42, 119.73, 125.40,

129.68, 141.67, 147.93, 150.77; EI-MS (70 eV) m/z (rel. in-

tensity, %) 204 (M⁺, 100), 190 (10), 189 (79), 161 (44), 146

(17), 143 (14), 133 (29), 118 (17), 115 (20); HRMS: calcd. for

C₁₂H₁₂O₃: 204.0786. Found: 204.0786.

MHz) d 1.69 (t, J = 7.0 Hz, 3H, OCH₂CH₃), 1.89 (dd, J = 5.6

Hz, 1.3 Hz, 3H, CH₃CH=CHCH₂), 3.69 (d, J = 6.3 Hz, 2H,

CH₃CH=CHCH₂), 4.15 (s, 3H, OCH₃), 4.33 (q, J = 7.0 Hz,

2H, OCH₂CH₃), 5.71 (dq, J = 13.2 Hz, 5.6 Hz, 1H,

CH₃CH=CHCH₂), 5.76 (dtq, J = 13.2 Hz, 6.3 Hz, 1.3 Hz, 1H,

CH₃CH=CHCH₂), 6.17 (dd, J = 10.3 Hz, 1.3 Hz, 1H,

ArCOCH=CH₂), 6.42 (dd, J = 17.0 Hz, 1.3 Hz, 1H,

ArCOCH=CH₂), 7.00, 7.26 (each s, 1H, H-3 and H-6), 7.04

(dd, J = 17.0 Hz, 10.3 Hz, 1H, ArCOCH=CH₂); ¹³C-NMR

(CDCl₃, 75 MHz), d 14.66, 17.76, 36.17, 55.82, 64.58,

113.41, 113.80, 126.33, 129.74, 129.92, 130.11, 134.69,

136.51, 145.61, 151.41, 194.83; EI-MS (70 eV) m/z (rel. in-

tensity, %) 260 (M⁺, 100), 245 (65), 231 (56), 219 (31), 217

(40), 205 (80), 203 (39), 191 (38), 190 (64), 177 (26), 175

(28), 145 (29), 115 (29); HRMS: calcd. for C₁₆H₂₀O₃:

260.1412. Found: 260.1412.

5-Ethoxy-6-methoxy-1-naphthol (15b)

Pure 15b (0.13 g, 61%) was obtained as colorless crys-

1

tals, mp 120-121 °C; R_f= 0.34 (EA/n-hexane = 1/4); H-

NMR (CDCl₃, 400 MHz) d 1.47 (t, J = 7.0 Hz, 3H, OCH₂CH₃),

3.97 (s, 3H, OCH₃), 4.19 (q, J = 7.0 Hz, 2H, OCH₂CH₃), 5.67

Syntheses of Substituted Naphthalenes and Naphthols

J. Chin. Chem. Soc., Vol. 51, No. 3, 2004 603

(br s, 1H, OH), 6.67, 7.25 (each d, J = 7.2 Hz, 1H, H-2 and

H-4), 7.27 (t, J = 7.2 Hz, 1H, H-3), 7.70, 7.94 (each d, J = 8.8

Hz, 1H, H-7 and H-8); ¹³C-NMR (CDCl₃, 100 MHz), d 15.75,

56.78, 69.32, 106.74, 114.11, 114.26, 118.16, 120.71,

126.20, 129.88, 141.74, 149.05, 151.65; (70 eV) m/z (rel. in-

tensity, %) 219 (M⁺¹, 10), 218 (83), 191 (10), 190 (100), 175

(21), 161 (16), 147 (58), 146 (13), 131 (10), 118 (14); HRMS:

calcd. for C₁₃H₁₄O₃: 218.0943. Found: 218.0944.

C₁₄H₁₆O₃: 232.1099. Found: 232.1099.

5-Benzyloxy-6-methoxy-4-methyl-1-naphthol (15f)

Pure 15f (0.12 g, 40%) was obtained as yellow liquid,

R_f= 0.25 (EA/n-hexane = 1/4); ¹H-NMR (CDCl₃, 400 MHz)

d 1.76 (s, 3H, CH₃), 3.99 (s, 3H, OCH₃), 5.17 (s, 2H,

OCH₂C₆H₅), 5.64 (br s, 1H, OH), 6.40, 6.91 (each d, J = 10.4

Hz, 1H, H-2 and H-3), 7.09, 8.01 (each d, J = 8.8 Hz, 1H, H-7

and H-8), 7.36-7.59 (m, 5H, OCH₂C₆H₅); ¹³C-NMR (CDCl₃,

100 MHz), d 23.46, 55.94, 74.77, 112.11, 124.55, 126.04,

127.50, 127.98, 128.18, 128.39, 128.45, 128.75, 128.92,

137.78, 145.78, 149.93, 151.59; (70 eV) m/z (rel. intensity,

%) 294 (M⁺, 11), 204 (13), 203 (100), 91 (73); HRMS: calcd.

for C₁₉H₁₈O₃: 294.1256. Found: 294.1250.

5-Benzyloxy-6-methoxy-1-naphthol (15c)

Pure 15c (0.16 g, 63%) was obtained as colorless crys-

1

tals, mp 122-123 °C; R_f= 0.33 (EA/n-hexane = 1/4); H-

NMR (CDCl₃, 400 MHz) d 3.99 (s, 3H, OCH₃), 5.15 (s, 2H,

OCH₂Ph), 5.45 (br s, 1H, OH), 6.66, 7.70 (each d, J = 8.0 Hz,

1H, H-2 and H-4), 7.29 (t, J = 8.0 Hz, 1H, H-3), 7.33, 7.96

(each d, J = 9.2 Hz, 1H, H-7 and H-8), 7.25-7.56 (m, 5H,

OCH₂C₆H₅); ¹³C-NMR (CDCl₃, 100 MHz), d 56.85, 75.27,

106.78, 114.17, 118.38, 120.68, 126.27, 127.90, 128.22,

128.37, 129.86, 130.98, 137.86, 141.74, 149.10, 151.56; (70

eV) m/z (rel. intensity, %) 280 (M⁺, 43), 202 (9), 189 (12),

161 (10), 131 (9), 118 (10), 91 (100); HRMS: calcd. for

C₁₈H₁₆O₃: 280.1099. Found: 280.1099.

6,7-Dimethoxy-1-naphthol (16a)¹⁹

Pure 16a (0.12 g, 60%) was obtained as colorless crys-

tals, mp 149-150 °C; R_f= 0.17 (EA/n-hexane = 1/4);

¹H-NMR (CDCl₃, 400 MHz) d 4.00, 4.02 (each s, 3H, OCH₃),

5.37 (br s, 1H, OH), 6.70, 7.29 (each d, J = 8.4 Hz, 1H, H-2

and H-4), 7.16 (t, J = 8.4 Hz, 1H, H-3), 7.10, 7.48 (each s, 1H,

H-5 and H-8); ¹³C-NMR (CDCl₃, 100 MHz), d 55.79, 55.88,

100.67, 106.25, 107.33, 119.15, 119.51, 124.19, 130.77,

149.01, 149.89, 150.45; EI-MS (70 eV) m/z (rel. intensity, %)

204 (M⁺, 100), 161 (38), 146 (13), 133 (17), 131 (20), 118

(19), 115 (11); HRMS: calcd. for C₁₂H₁₂O₃: 204.0786. Found:

204.0786.

5,6-Dimethoxy-4-methyl-1-naphthol (15d)

Pure 15d (0.10 g, 46%) was obtained as yellow liquid,

R_f= 0.31 (EA/n-hexane = 1/4); ¹H-NMR (CDCl₃, 400 MHz)

d 2.78 (s, 3H, ArCH₃), 3.87, 3.95 (each s, 3H, OCH₃), 5.35 (br

s, 1H, OH), 6.54, 6.95 (each d, J = 10.4 Hz, 1H, H-2 and H-3),

7.22, 8.02 (each d, J = 8.8 Hz, 1H, H-7 and H-8); ¹³C-NMR

(CDCl₃, 100 MHz), d 22.97, 56.53, 61.16, 106.16, 113.22,

119.01, 121.79, 124.96, 128.81, 129.36, 144.84, 150.15,

150.25; (70 eV) m/z (rel. intensity, %) 219 (M⁺¹, 100), 218

(27), 205 (18), 204 (29), 203 (28), 175 (16), 115 (11); HRMS:

calcd. for C₁₃H₁₄O₃: 218.0943. Found: 218.0943.

7-Ethoxy-6-methoxy-1-naphthol (16b)

Pure 16b (0.15 g, 68%) was obtained as colorless crys-

1

tals, mp 161-162 °C; R_f= 0.16 (EA/n-hexane = 1/4); H-

NMR (CDCl₃, 400 MHz) d 1.53 (t, J = 7.0 Hz, 3H, OCH₂CH₃),

3.98 (s, 3H, OCH₃), 4.25 (q, J = 7.0 Hz, 2H, OCH₂CH₃), 5.47

(br s, 1H, OH), 6.68, 7.28 (each d, J = 8.4 Hz, 1H, H-2 and

H-4), 7.15 (t, J = 8.4 Hz, 1H, H-3), 7.10, 7.48 (each s, 1H, H-5

and H-8); ¹³C-NMR (CDCl₃, 100 MHz), d 14.60, 55.80,

64.19, 101.63, 106.34, 107.25, 119.07, 119.60, 124.10,

130.68, 148.27, 150.06, 150.48; (70 eV) m/z (rel. intensity,

%) 219 (M⁺¹, 13), 218 (91), 191 (12), 190 (100), 175 (20), 161

(14), 147 (48), 146 (13), 131 (11), 118 (12); HRMS: calcd. for

C₁₃H₁₄O₃: 218.0943. Found: 218.0945.

5-Ethoxy-6-methoxy-4-methyl-1-naphthol (15e)

Pure 15e (0.13 g, 62%) was obtained as colorless crys-

tals, mp 112-113 °C; R_f= 0.27 (EA/n-hexane = 1/4); ¹H-NMR

(CDCl₃, 400 MHz) d 1.46 (t, J = 7.0 Hz, 3H, OCH₂CH₃), 2.81

(s, 3H, ArCH₃), 3.98 (s, 3H, OCH₃), 4.06 (q, J = 7.0 Hz, 2H,

OCH₂CH₃), 5.27 (br s, 1H, OH), 6.55, 6.99 (each d, J = 7.2

Hz, 1H, H-2 and H-3), 7.26, 7.99 (each d, J = 9.2 Hz, 1H, H-7

and H-8); ¹³C-NMR (CDCl₃, 100 MHz), d 15.37, 23.31,

56.70, 69.37, 106.07, 113.57, 118.56, 121.70, 125.75,

128.56, 129.88, 144.09, 149.78, 150.54; (70 eV) m/z (rel. in-

tensity, %) 232 (M⁺, 56), 204 (21), 203 (100), 189 (24), 175

(17), 160 (20), 131 (20), 115 (21); HRMS: calcd. for

7-Benzyloxy-6-methoxy-1-naphthol (16c)

Pure 16c (0.17 g, 62%) was obtained as colorless crys-

1

tals, mp 156-157 °C; R_f= 0.19 (EA/n-hexane = 1/4); H-

NMR (CDCl₃, 400 MHz) d 3.97 (s, 3H, OCH₃), 5.24 (s, 2H,

OCH₂Ph), 5.50 (br s, 1H, OH), 6.65, 7.27 (each d, J = 9.0 Hz,

604 J. Chin. Chem. Soc., Vol. 51, No. 3, 2004

Huang et al.

1H, H-2 and H-4), 7.13 (t, J = 9.0 Hz, 1H, H-3), 7.29-7.49 (m,

5H, OCH₂C₆H₅), 7.11, 7.54 (each s, 1H, H-5 and H-8);

¹³C-NMR (CDCl₃, 100 MHz), d 55.83, 70.66, 102.75, 106.56,

107.30, 119.04, 119.50, 124.29, 127.57, 127.89, 128.51,

130.91, 136.72, 148.11, 150.25, 150.51; EI-MS (70 eV) m/z

(rel. intensity, %) 280 (M⁺, 43), 189 (12), 161 (10), 131 (9),

118 (10), 91 (100); HRMS: calcd. for C₁₈H₁₆O₃: 280.1099.

Found: 280.1100.

ACKNOWLEDGEMENT

We are thankful to Prof. Michael Yen Nan Chiang, and

Mr. Jing-Yun Wu (Sun Yat-Sen University, Taiwan) for X-ray

crystallographic analysis. We are also grateful to Prof.

Yamazaki Takao, the Emeritus Prof. of Toyama Medical and

Pharmaceutical University, and Prof. Takahata Hiroki,

Tohoku Pharmaceutical University, Japan for encourage-

ment. Financial support from the NSC, Taiwan, is gratefully

acknowledged.

X-ray Crystal Structure Determination of Naphthalenes

(9f)

A colorless plate crystal of C₁₉H₁₈O₂(9f) was obtained

by recrystallization from ethylacetate. Data collection was

performed at 293 ± 1 K. The crystal (0.20 ´ 0.60 ´ 0.80 mm)

belongs to the orthorhombic system, space group P2₁2₁2₁,

with a = 5.148(2) Å, b = 9.910(2) Å, c = 28.892(2) Å, V =

1474.1(6) Å³, Z = 4, D_calcd= 1.254 g/cm³, l(Mo-Ka) =

0.71069 Å. Intensity data were measured on a Rigaku AFC7S

diffractometer 2q of 52.0°. A total of 1757 reflections were

collected. The structure was solved by direct methods

(SIR92) and refined by a full-matrix least-squares procedure.

The non-hydrogen atoms were given anisotropic thermal pa-

rameters. The refinement converged to a final R = 0.062, R_w=

0.094 for 1276 observed reflections [I > 3.00 s(I)] and 160

variable parameters.

Received September 9, 2003.

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Syntheses of substituted naphthalenes and naphthols

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