Synthesis and biological evaluation of C1-O-substituted-3-(3-butylamino-2-hydroxy-propoxy)-xanthen-9-one as topoisomerase IIα catalytic inhibitors

Article abstract of DOI:10.1016/j.ejmech.2016.07.046

Topoisomerase II poison blocks the transitorily generated DNA double-strand breaks (DSBs) from religation, thereby causes severe DNA damage and gene toxicity. While topoisomerase II catalytic inhibitor does not form cleavable DNA-enzyme complex because its function attributes to inhibition of the catalytic steps of the enzyme such as before generating DNA DSBs or in the last step of the catalytic cycle after religation. It has been reported that the stabilizing effect of etoposide on transient cleavable DNA-topoisomerase IIβ complex attributes to its secondary malignancy. Therefore, topoisomerase IIα has been considered as more attractive target than topoisomerase IIβ for the development of chemotherapeutic agents. In the previous work, we reported compounds I and II as novel topoisomerase IIα catalytic inhibitors targeting for ATP binding site of human topoisomerase IIα ATP-binding domain. As a continuous work, we have designed and synthesized 43 compounds of C1-O-alkyl and arylalkyl substitiuted compounds with or without methoxy group on ring A. In the topoisomerase IIα inhibitory test, among the tested C1-O-4-chlorophenethyl substituted compounds 37 and 47 were more active than others, and compound 37 showed strongest topoisomerase IIα inhibitory activity with 94.4% and 23.0% inhibition, respectively, at 100 and 20?μM. Compounds 37 and 47 have also showed much enhanced cytotoxic activity against T47D cells; IC₅₀(μM): 0.63?±?0.01 and 0.19?±?0.02, respectively, which are stronger than reference drugs. Band depletion assay and cleavage complex assay results showed compounds 37 and 47 were potential topoisomerase IIα catalytic inhibitor with low DNA damage.

Full text of DOI:10.1016/j.ejmech.2016.07.046

Accepted Manuscript
Synthesis and biological evaluation of C1-Osubstituted-3-(3-butylamino-2-hydroxy-
propoxy)-xanthen-9-one as topoisomerase IIα catalytic inhibitors
Seojeong Park, Eunji Hong, Soo Yeon Kwak, Kyu-Yeon Jun, Eung-Seok Lee,
Youngjoo Kwon, Younghwa Na
PII:
S0223-5234(16)30607-9
10.1016/j.ejmech.2016.07.046
EJMECH 8764
DOI:
Reference:
To appear in: European Journal of Medicinal Chemistry
Received Date: 16 May 2016
Revised Date: 6 July 2016
Accepted Date: 20 July 2016
Please cite this article as: S. Park, E. Hong, S.Y. Kwak, K.-Y. Jun, E.-S. Lee, Y. Kwon, Y. Na, Synthesis
and biological evaluation of C1-Osubstituted-3-(3-butylamino-2-hydroxy-propoxy)-xanthen-9-one as
topoisomerase IIα catalytic inhibitors, European Journal of Medicinal Chemistry (2016), doi: 10.1016/
j.ejmech.2016.07.046.
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ACCEPTED MANUSCRIPT
Eur. J. Med. Chem.
Synthesis and Biological Evaluation of C1-O-Substituted-3-(3-Butylamino-2-hydroxy-
propoxy)-xanthen-9-one as topoisomerase IIα catalytic inhibitors
1
,#
2,#
2
1
3
Seojeong Park, Eunji Hong, Soo Yeon Kwak, Kyu-Yeon Jun, Eung-Seok Lee,
1,
2,
Youngjoo Kwon, * Younghwa Na *
1
College of Pharmacy & Graduate School of Pharmaceutical Sciences, Ewha Womans
2
University, Seoul 120-750, Korea, College of Pharmacy, CHA University, Pocheon, 487-010,
3
Korea, College of Pharmacy, Yeungnam University, Gyeongsan, 712-749, Korea.
*
3
3
To whom correspondence should be addressed. Y. Na: Phone: 82-31-8017-9896. Fax: 82-
1-8017-9420. E-mail: yna7315@cha.ac.kr, Y. Kwon: Phone: 82-2-3277-4653. Fax: 82-2-
277-3051. E-mail: ykwon@ewha.ac.kr.
#
These authors equally contributed to this work.

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Abstract
Topoisomerase II poison blocks the transitorily generated DNA double-strand breaks (DSBs)
from religation, thereby causes severe DNA damage and gene toxicity. While topoisomerase
II catalytic inhibitor does not form cleavable DNA-enzyme complex because its function
attributes to inhibition of the catalytic steps of the enzyme such as before generating DNA
DSBs or in the last step of the catalytic cycle after religation. It has been reported that the
stabilizing effect of etoposide on transient cleavable DNA-topoisomerase IIβ complex
attributes to its secondary malignancy. Therefore, topoisomerase IIα has been considered as
more attractive target than topoisomerase IIβ for the development of chemotherapeutic agents.
In the previous work, we reported compounds I and II as novel topoisomerase IIα catalytic
inhibitors targeting for ATP binding site of human topoisomerase IIα ATP-binding domain. As
a continuous work, we have designed and synthesized 43 compounds of C1-O-alkyl and
arylalkyl substitiuted compounds with or without methoxy group on ring A. In the
topoisomerase IIα inhibitory test, among the tested C1-O-4-chlorophenethyl substituted
compounds 37 and 47 were more active than others, and compound 37 showed strongest
topoisomerase IIα inhibitory activity with 94.4% and 23.0% inhibition, respectively, at 100
and 20 µM. Compounds 37 and 47 have also showed much enhanced cytotoxic activity
against T47D cells; IC (µM): 0.63 ± 0.01 and 0.19 ± 0.02, respectively, which are stronger
5
0
than reference drugs. Band depletion assay and cleavage complex assay results showed
compounds 37 and 47 were potential topoisomerase IIα catalytic inhibitor with low DNA
damage.

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Keywords: C1-alkyl and arylalkyl substitiued xanthones, anticancer agents, Topoisomerase
IIα catalytic inhibitor
Introduction
Xanthones are hetero-tricyclic planar compounds originally isolated as secondary metabolites
from a few higher plant families, fungi and lichen [1] and are named after ‘Xanthos’ which
means yellow in Greek [2]. Diverse pharmacological profiles of xanthone families have been
reported including anti-hypertensive [3], anticonvulsant [4], antithrombotic [5],
anticholinesterase [6], anticancer activities [7, 8] affected by the substituents. The simplicity
of structure and interesting diverse biological activities of xanthones have attracted
researchers to put much effort for finding new potential druggable compounds via synthetic
derivatization or isolation from natural resources.
In the cell proliferation process tangled DNA should overcome the topology problem, which
could be solved by topoisomerase enzymes well-known to be taking part in DNA relaxation,
supercoiling, catenation/decatenation and knotting/unknotting [9, 10]. Topoisomerases are
ubiquitous enzymes and responsible for the topological inter-conversions of DNA by
generating transient breaks of DNA strands. Human topoisomerase operates in two different
ways. One causes single-strand breaks (SSBs, called type I), and the other induces double-
strand breaks (DSBs, type II), during cell proliferation processes [11, 12]. Between these two
types of topoisomerase, topoisomerase II is essential to relax supercoiled DNA through
catalytic cycle of DSBs [13]. There are two isoforms of topoisomerase II, α and β forms.
Despite their similarities, the two enzymes have distinct patterns of expression and
physiological functions in vertebrate cells [14-17]. Topoisomerase IIα is essential for the
survival of actively growing cells and able to decatenate the replicated chromosomes during
chromosome segregation process. Thus the expression level of topoisomerase IIα are up-

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regulated dramatically during cell proliferation [18-20]. Furthermore, the expression level of
topoisomerase IIα changes over the cell cycle and reaches a maximum point in the late S and
G /M phase [20-22]. Topoisomerase IIα is found at replication forks and remains tightly
2
associated with chromosomes during mitosis [23, 24]. In contrast, expression of the β isoform
is independent of proliferative status of cells and the enzyme dissociates from chromosomes
during mitosis [17, 19, 23]. Topoisomerase IIβ has been known to be related with toxicity of
topoisomerase II targeting anticancer drugs such as cardiotoxicity and potential development
of secondary malignancy during their medication. Therefore, topoisomerase IIα has been
considered as more attractive target than topoisomerase IIβ for the development of
chemotherapeutic agents [25-27].
Topoisomerase II inhibitors act in two different pathways; (1) the distinct character of
topoisomerase II poison is to bind and stabilize transiently and covalently formed DNA-
enzyme complex and (2) topoisomerase II catalytic inhibitor does not stabilize the DNA-
enzyme complexes but eliminates essential catalytic activities of topoisomerase II.
Topoisomerase II poison blocks the transitorily generated DNA DSB from religation, thereby
causes severe DNA damage and gene toxicity [28]. While topoisomerase II catalytic inhibitor
does not form cleavable DNA-enzyme complex because its function attributes to inhibition of
the catalytic steps of the enzyme such as before generating DNA DSBs or in the last step of
the catalytic cycle after religation [10, 29-31]. It has been reported that the stabilizing effect
of etoposide on transient cleavable DNA-topoisomerase IIβ complex attributes to its
secondary malignancy [26, 27].

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In the previous work, we reported compounds I and II as novel topoisomerase IIα
catalytic inhibitors targeting for ATP binding site of human topoisomerase IIα ATP-binding
domain [32, 33]. We extended our interest in the current study to discover human
topoisomerase IIα catalytic inhibitor with improvement on catalytic inhibition and reduction
of toxicity likely caused by DNA DSBs and to evaluate the mode of action. Based on the
previous molecular docking study result of compound I with human topoisomerase IIα ATP-
binding domain, we have designed and synthesized a series of C1-O-alkyl and arylalkyl
substitiuted compounds (n-butylamine mediated epoxide ring opened derivatives) with or
without methoxy group on ring A.
2
. Chemistry
Synthesis of Target Compounds: General synthetic methods for the proposed compounds
are depicted in Scheme 1. Group I compounds are prepared as two-step process. First,
epichlorohydrin coupling reaction at C-3 hydroxy group under basic condition, and then
subsequent C-1-O-alkylation. Group II compounds are obtained by n-butylamine mediated
epoxide ring opening reaction in methanol solvent (Scheme 1).
Starting compounds 3 and 4 were synthesized by previous method [32], and then different
length of alkyl halide (alkyl = ethyl, isopropyl, butyl, and pentyl) or arylalkyl halide (benzyl,
3
-chlorobenzyl,
3-methoxybenzyl,
4-methoxybenzyl,
3-trifluoromethylbenzyl,
3-
chlorophenethyl, and 4-chlorophenethyl) were mixed with Cs CO or K CO in acetone/DMF
2
3
2
3
and then refluxed to give Group I compounds in 5.6-75.2% yields after purification. In the
1
H-NMR spectrum, proton peaks of alkyl group in compounds 5-8 and 16-19 were confirmed.
Compounds 9-13 and 20-24 showed singlet peak which presents two methylene protons of

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benzyl at 5.2 ppm. Compounds 14, 15, 25, and 26 showed two triplet peaks belonging to the
ethylene of phenethyl group at 3.2 and 4.2 ppm, respectively. All the Group II compounds
have a multiplet peak of methine hydrogen on the epoxide ring at 3.4 ppm. Subsequent
epoxide ring opening reaction of Group I with n-butylamine (10 equiv.) was accomplished in
1
3
MeOH solvent to give Group II compounds in 19.1-90.2% yields. In the C-NMR spectrum,
the methine carbon of opened epoxide ring was down-field shifted from 50.0 to 69.9 ppm.
Structures of all the prepared compounds are depicted in Scheme 2.
O
O
OR2
O
O
OR2
Epichlorohydrin
K CO , Acetone/DMF
2
3
O
O
O
O
R1
R1
1
2
R = H
R = OCH
1
3 R = H
1
1
3
4 R = OCH
1 3
R -X
2
Cs CO3
2
Acetone/DMF
O
OR2
O
O
OR2
n-Butylamine
MeOH
O
O
NH(CH ) CH
3
O
2
3
O
R1
OH
R1
Scheme 1. General synthetic method of compounds

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Group I
O
O
OR2
O
O
R1
5
6
7
8
9
1
1
1
1
1
1
R = H, R = C H
16 R = OCH , R = C H
1 3 2 2 5
1
2
2
5
R = H, R = i-C H
17 R = OCH , R = i-C H
1
2
3
7
1 3 2 3 7
R = H, R = C H
18 R = OCH , R = C H
1 3 2 4 9
1
2
4
9
R = H, R = C H
19 R = OCH , R = C H
1
2
5
11
1 3 2 5 11
R = H, R = benzyl
20 R = OCH , R = benzyl
1 3 2
1
2
0 R = H, R = 3-chlorobenzyl
21 R = OCH , R = 3-chlorobenzyl
1
2
1 3 2
1 R = H, R = 3-methoxybenzyl
22 R = OCH , R = 3-methoxybenzyl
1 3 2
1
2
2 R = H, R = 4-methoxybenzyl
23 R = OCH , R = 4-methoxybenzyl
1
2
1 3 2
3 R = H, R = 3-trifluoromethylbenzyl
24 R = OCH , R = 3-trifluoromethylbenzyl
1 3 2
1
2
4 R = H, R = 3-chlorophenethyl
25 R = OCH , R = 3-chlorophenethyl
1
2
1 3 2
5 R = H, R = 4-chlorophenethyl
26 R = OCH , R = 4-chlorophenethyl
1 3 2
1
2
O
O
OR2
Group II
O
NH(CH ) CH
2 3 3
R1
OH
2
2
2
3
3
3
3
3
3
3
3
7 R = H, R = C H
38 R = OCH , R = C H
1 3 2 2 5
1
2
2
5
8 R = H, R = i-C H
39 R = OCH , R = i-C H
1
2
3
7
1 3 2 3 7
9 R = H, R = C H
40 R = OCH , R = C H
1 3 2 4 9
1
2
4
9
0 R = H, R = C H
41 R = OCH , R = C H
1
2
5
11
1 3 2 5 11
1 R = H, R = benzyl
42 R = OCH , R = benzyl
1 3 2
1
2
2 R = H, R = 3-chlorobenzyl
43 R = OCH , R = 3-chlorobenzyl
1
2
1 3 2
3 R = H, R = 3-methoxybenzyl
44 R = OCH , R = 3-methoxybenzyl
1 3 2
1
2
4 R = H, R = 4-methoxybenzyl
45 R = OCH , R = 4-methoxybenzyl
1
2
1 3 2
5 R = H, R = 3-trifluoromethylbenzyl
46 R = OCH , R = 3-trifluoromethylbenzyl
1 3 2
1
2
6 R = H, R = 3-chlorophenethyl
47 R = OCH , R = 4-chlorophenethyl
1
2
1 3 2
7 R = H, R = 4-chlorophenethyl
1
2
Scheme 2. Structures of the prepared compounds
3
3
. Results and Discussion
.1. Human Topoisomerase IIα Inhibitory Activities of Compounds
In the topoisomerase IIα inhibitory activity test, Group II compounds (epoxide ring opened
compounds) showed stronger activity than Group I at 100 µM. In the group II series, C1-O-

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arylalkyl substituted compounds (31-37 and 42-47) were better than corresponding alkyl
substituted ones (27-30 and 38-40). Compounds without 5-methoxy group also showed more
efficient topoisomerase IIα inhibitory activity than 5-methoxy analogues except C1-O-(3-
chloropheneyl) substituted compounds. Overall, C1-O-arylalkyl substituents enhanced
enzyme inhibitory activity than alkyl substituted analogues. But the length difference
between oxygen and aryl group, methylene and ethylene, did not show clear information.
Although the effect of substituents on inhibitory activity was not consistent to make a solid
structure and activity relationship, C1-O-4-chlorophenethyl substituted compounds 37 and 47
were more active than others, H, OCH , CF in each series (Table 1 & Figure 1). In this test,
3
3
among the tested compounds compound 37 showed strongest topoisomerase IIα inhibitory
activity with 94.4% and 23.0% inhibition, respectively, at 100 and 20 µM treatment.
Insert Figure 1 and Table 1
3
.2. Cytotoxicity of the Compounds
The cytotoxicity assay for compounds was conducted with a range of human tumor cell lines,
HCT15 (colon) T47D (breast), HeLa (cervical) and NCI-N87 (stomach). The inhibitory
activities are presented as IC (µM) and listed in Table 2.
5
0
Insert Table 2
Overall, compounds tested showed good anticancer activity. In Group II, C1-O-arylalkyl
derivatives efficiently suppressed cell growth in the tested cell lines, which was better than
corresponding C1-O-alkly ones. 5-Methoxy-3-epoxide substituted compounds 16-25 in
Group I showed hundreds nanomolar IC values in HCT15, which are better than etoposide
5
0

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and similar to adriamycin used as references. Compounds 37 and 47, strongest topoisomerase
IIα inhibitors among C5-H and C5-methoxy series compounds, also showed much enhanced
cytotoxic activity against T47D cells; IC (µM): 0.63 ± 0.01 and 0.19 ± 0.02, respectively,
5
0
which are stronger than reference drugs.
3
.3 Band depletion assay of the selected compounds 36, 37, and 47
With compound 37 possessing the strongest topoisomerase IIα DNA relaxation inhibitory
activity and compound 47 showing most efficient cytotoxicity against T47D human breast
cancer cells, compound 36 was additionally selected for further experiments to determine
their mode of action clearly. The structural difference of 36 vs 37 and 47 is the position of
chlorine and that of 36 vs 47 is the addition of methoxy group in R1 position of ring A. First
of all, to verify whether compounds 36, 37 and 47 function as topoisomerase IIα poisons or
catalytic inhibitors, T47D cells were treated with 50 µM of each of compounds and etoposide
for 2 hours and followed by cell harvest and cell lysis. The covalently bound topoisomerase
IIα to DNA was excluded during DNA removal process while the free topoisomerase IIα was
detected by Western blot analysis. As shown in Figure 2, the western blot band of free
topoisomerase IIα was depleted in the etoposide (a well-known topoisomerase II poison)-
treated T47D cells while it was evidently observed in compounds 36, 37 and 47 -treated cells
(Figure 2). This result suggests compounds 36, 37 and 47 inhibited the catalytic activity of
topoisomerase IIα without stabilizing DNA-topoisomerase IIα cleavable complex.
Insert Figure 2

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3
.4 Cleavable complex assay of the selected compounds 36, 37 and 47
The function of compounds 36, 37 and 47 as topoisomerase IIα catalytic inhibitors was
revalidated with cleavable complex assay. Etoposide evidently generated the linear truncated
DNA because it stabilized the transiently formed DNA-topoisomerase IIα cleavable complex
then blocked DNA from religation as shown in Figure 3. However the treatment of
compounds 36, 37 and 47 as the same concentration as etoposide did not make the linear
DNA (Figure 3). This result is consistent with that of band depletion assay.
Insert Figure 3
3
.5. Comet assay of the selected compounds 36, 37 and 47
Based on results from topoisomerase IIα relaxation assay, DNA band depletion assay and
cleavable complex assay, compounds 36, 37 and 47 were characterized as human
topoisomerase IIα catalytic inhibitors. The most difference of topoisomerse IIα catalytic
inhibitor over topoisomerase IIα poison is no generation of undesired DNA truncation in
which catalytic inhibitors can be advantageous over poisons. Topoisomerase IIα poisons
produce in general serious DNA damage induced by stabilizing the cleavable complex
followed by preventing the religation of DNA double strand breaks [34]. Compounds 36, 37
and 47 were evaluated with comet assay in T47D cells to further confirm its mode of action
as a topoisomerase IIα catalytic inhibitor because selected compounds showed stronger
toxicity in T47D cells among tested human cancer cell lines (Table 2). As shown in Figure 4,
the image of inverted fluorescence microscope and the result of image analysis using Komet
5
.0 software showed that etoposide made serious comet formation due to its mode of action
to generate un-religated short DNA but compounds tested did not at the same treatment of 5

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and10 ꢀM for 24 h, which further confirms the catalytic inhibitory activity of compounds 36,
3
7 and 47.
3
.5. Molecular Docking Study
Docking study was carried out for compound 36, 37 and 47 into the ATP-binding domain
of human topoisomerase IIα. The analysis of the docked compounds to the ATP binding site
of topoisomerase IIα showed that compound 37 has lowest binding energy of -8.45 kcal/mol
(Ki = 636.14 nM) (Figure 5A) among four compounds. The only difference between
compound 36 and 37 is the chloro substitution on the phenylethoxy group. However,
comparing the docked structure, the xanthone ring of compound 36 did not overlap well with
purine ring, and there was no hydrogen bond interaction with topoisomerase IIα. The docking
was further analyzed by comparing with the AMP-PNP, and it showed that the xanthone ring
overlaps with purine ring. Residues that are in close contact with compound 37 are Asn91,
Asp94, Asn120, Val137, Ile141, Phe142, Thr147, Ser149, Ala167, Lys168, and Thr215
(Figure 5B). There is hydrogen bond interaction between C3-O with Lys168. Also, the amide
group and Asn91 and the hydroxyl group with Ala167 have hydrogen bond interactions. The
chloro group on the C1-O substituted benzene ring may be changed with more polar group
since it protrudes out to the solvent accessible area.
4
. Conclusion
While topoisomerase II poison blocks the transitorily generated DNA DSB from religation,
thereby causes severe DNA damage and gene toxicity, topoisomerase II catalytic inhibitor
does not form cleavable DNA-enzyme complex because its function attributes to inhibition of
the catalytic steps of the enzyme such as before generating DNA DSBs or in the last step of
the catalytic cycle after relegation. It has been reported that the stabilizing effect of etoposide

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on transient cleavable DNA-topoisomerase IIβ complex attributes to its secondary
malignancy. Therefore, topoisomerase IIα has been considered as more attractive target than
topoisomerase IIβ for the development of chemotherapeutic agents. As c continuous work to
find efficient topoisomerase IIα catalytic inhibitor, we have designed and synthesized 43
compounds of C1-O-alkyl and arylalkyl substitiuted compounds based on compound I and II.
In the topoisomerase IIα inhibitory test, although the structure and activity relationship of the
series compounds was not consistent, compounds 37 and 47 exhibited superior inhibitory
activity among the tested compounds and especially compound 37 showed strongest
topoisomerase IIα inhibitory activity with 94.4% and 23.0% inhibition, respectively, at 100
and 20 µM. In the anticancer activity test, C1-O-arylalkyl derivatives in Group II efficiently
suppressed cell growth in the tested cell lines, which was better than corresponding C1-O-
alkly ones. Especially compounds 37 and 47 had IC (µM) of 0.63 ± 0.01 and 0.19 ± 0.02,
5
0
respectively, against T47D cells. 5-Methoxy-3-epoxide substituted compounds 16-25 in
Group I showed hundreds nanomolar IC values in HCT15, which are better than etoposide
5
0
and similar to adriamycin used as references. Band depletion assay result suggests
compounds 36, 37 and 47 inhibit the catalytic activity of topoisomerase IIα without
stabilizing DNA-topoisomerase IIα cleavable complex. Cleavage complex assay results also
showed compounds 36, 37 and 47 were potential topoisomerase IIα catalytic inhibitor, which
is consistent with that of band depletion assay. The advantage of topoisomerase IIα catalytic
inhibitor over topoisomerase IIα poison is no generation of undesired DNA truncation, which
can be confirmed by comet assay. Etoposide made serious comet formation due to its mode of
action to generate un-religated short DNA but compounds 36, 37 and 47 did not. Molecular
docking analysis compound 37 to the ATP binding site of topoisomerase IIα showed that
compound 37 has low binding energy. Overall C1-O- arylalkyl substitiuted compounds were

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potential topoisomerase IIα catalytic inhibitor and compound 37 could be starting point for
the efficient modification in this scaffold.
5
5
. Experimental
.1. Chemistry general
Most chemicals and reagents used were obtained from Aldrich Chemical Co. and others
were from company like TCI. Melting points were measured without correction in open
capillaries with Barnstead Electrothermal melting point apparatus, Manual MEL-TEMP
(
Model No: 1202D). Chromatographic separations were monitored by thin-layer
chromatography using a commercially available pre-coated Merck Kieselgel 60 F254 plate
0.25mm) and detected by visualizing under UV at 254 and 365 nm. Silicagel column
(
chromatography was carried out with Merck Kieselgel 60 (0.040 - 0.063 mm). All solvents
used for chromatography were directly used without distillation. The purity was assessed by
HPLC (Shimadzu LC-20AD) analysis under the following conditions; column, SunFire C18
(4.6 mm × 150 mm, 5 um); mobile phase, condition A: A (water) and B (acetonitrile) using a
linear gradient of 50 - 70% B in 0 - 15 min, 70% B in 15 - 20 min, 100% B in 20 - 25 min
and 50% B in 25 - 30 min, condition B: A (0.2% (v/v) TFA in water) and B (acetonitrile)
using a linear gradient of 50 - 70% B in 0 - 15 min, 70% B in 15 - 20 min, 100% B in 20 - 25
min and 50% B in 25 - 30 min, flow rate; 1.0 mL/min; detection, diode array detector
(Shimadzu Spd-M20A). The purity of compound is described as percent (%) and retention
1
time was given in minutes. NMR spectra were recorded on Varian AS 400 ( H-NMR at 400
1
3
MHz and C-NMR at 100 MHz) with tetramethylsilane as an internal standard. Chemical
shift (δ) values are expressed in ppm and coupling constant (J) values in hertz (Hz). The
melting points were measured on Gallenkamp Melting Point Apparatus without correction.

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5
5
.2. General synthetic methods for 1,3-dihydroxyxanthone analogues
.2.1. 1,3-Dihydroxy-xanthen-9-one (1)
The reaction mixture of salicylic acid (2.06 g, 14.89 mmol), phloroglucinol (2.01 g, 15.94
mmol) and ZnCl (4.93 g, 39.04 mmol) in POCl (30 mL) was refluxed (4 h) at 80 °C, cooled
2
3
to room temperature and then poured into iced water very slowly. The solid formed was kept
for 1 d at 4 °C, collected and washed with water to give a red solid. After drying under
vacuum, the crude product was purified by silica gel column chromatography (eluent: ethyl
acetate/n-hexane = 1:2) to give compound 1 as a pale yellow solid (0.73 g, 26.5%). m.p. 253-
1
2
55 °C; R 0.66 (eluent: ethyl acetate/n-hexane = 1:1); H-NMR (CDCl , 400 MHz) δ 6.21 (d,
f
3
J = 2.4 Hz, 1H), 6.31 (d, J = 2.0 Hz, 1H), 7.30 (ddd, J = 1.2, 7.2, 8.0 Hz, 1H), 7.32 (dd, J =
0
1
1
.4, 8.4 Hz, 1H), 7.62 (ddd, J = 2.0, 7.2, 6.8 Hz, 1H), 8.13 (dd, J = 2.0, 8.0 Hz, 1H), 10.10 (s,
13
H), 12.76 (s, 1H); C-NMR (CDCl , 100 MHz) 94.4, 98.6, 103.1, 117.5, 120.6, 123.8,
3
25.7, 134.8, 155.9, 157.9, 163.6, 165.8, 180.5 ppm.
5
.2.2. 1,3-Dihydroxy-5-methoxy-xanthen-9-one (2)
2
,3-dimethoxybenzoic acid (2.01 g, 11.0 mmol), phloroglucinol (2.14 g, 17.0 mmol) and
ZnCl (8.98 g, 65.9 mmol) in POCl (30 mL) was refluxed (4 h) at 80 °C, cooled to room
2
3
temperature and then poured into iced water very slowly. The solid formed was kept for 1 d
at 4 °C, collected and washed with water to give a red solid. After drying under vacuum, the
crude product was purified by silica gel chromatography (eluent: ethyl acetate/n-hexane = 1:2)
to give compound 2 as a pale yellow solid (0.78 g, 27.5%). m.p 286-288 °C; R 0.55 (eluent:
f
1
ethyl acetate/n-hexane = 1:1); H-NMR (CDCl , 400 MHz) δ 3.96 (s, 3H), 6.17 (d, J = 2.4 Hz,
3
1
H), 6.37 (d, J = 2.4 Hz, 1H), 7.31 (t, J = 8.0 Hz, 1H), 7.37 (dd, J = 1.2, 8.0 Hz, 1H), 7.66 (dd,
1
3
J = 1.2, 8.0 Hz, 1H), 10.82 (s, 1H), 12.76 (s, 1H); C-NMR (CDCl , 100 MHz) 55.9, 93.9,
3

ACCEPTED MANUSCRIPT
9
8.1, 102.1, 115.6, 115.9, 120.6, 123.4, 145.4, 147.8, 157.0, 162.8, 165.6, 179.6 ppm.
5
.3. General method for synthesis of epichlorohydrin analogues
A mixture of compound 1 or 2, epichlorohydrin (1.5 equiv.) and K CO (2 equiv.) in
2
3
acetone/DMF (10 mL/10 mL) was refluxed (20 h). The reaction was quenched with water (30
mL) and extracted with ethyl acetate (× 3). The organic layer was collected and washed with
brine, and then dried over anhydrous MgSO . Solvent was removed under reduced pressure
4
and residue was purified by silica gel column chromatography (eluent: CHCl3).
5
.3.1. 1-Hydroxy-3-oxiranylmethoxy-xanthen-9-one (3)
Following the general method, compound 1 (1.01 g, 4.44 mmol), epichlorohydrin (0.83 g,
.93 mmol) and K CO (1.32 g, 9.56 mmol) was used. The purification was conducted with
8
2
3
eluent (CHCl ) to give compound 15 (0.73 g, 57.8%) as a pale yellow solid. R 0.76 (DCM);
3
f
1
H-NMR (CDCl , 400 MHz) δ 2.79 (dd, J = 2.4, 4.8 Hz, 1H), 2.96 (dd, J = 4.0, 4.0 Hz, 1H),
3
3
.38-3.41 (m, 1H), 4.01 (dd, J = 6.0, 11.2 Hz, 1H), 4.34 (dd, J = 3.2, 11.2 Hz, 1H), 6.36 (d, J
2.0 Hz, 1H), 6.46 (d, J = 2.4 Hz, 1H), 7.38 (ddd, J = 1.2, 7.2, 7.6 Hz, 1H), 7.43 (dd, J = 0.4,
=
13
7
.6 Hz, 1H), 7.72 (ddd, J = 1.6, 7.2, 7.6 Hz, 1H), 8.24 (dd, J = 1.6, 8.0 Hz, 1H); C-NMR
(
CDCl , 100 MHz) 44.8, 49.9, 69.5, 93.6, 97.7, 104.5, 117.8, 120.9, 124.3, 126.1, 135.3,
3
1
56.3, 157.9, 163.9, 16.6, 181.1 ppm.
5
.3.2. 1-Hydroxy-5-methoxy-3-oxiranylmethoxy-xanthen-9-one (4)
Following the general method, compound 2 (0.31 g, 1.21 mmol), epichlorohydrin (0.24g,
.55 mmol) and K CO (0.38 g, 2.75 mmol) was used. The purification was conducted with
2
2
3
eluent (CHCl ) to give compound 13 (0.12 g, 32.3%) as a pale yellow solid. R 0.30 (DCM);
3
f
1
H-NMR (CDCl 400 MHz) δ 2.78 (dd, J = 2.4, 4.8 Hz, 1H), 2.94 (t, J = 4.8 Hz, 1H), 3.39-
3
,

ACCEPTED MANUSCRIPT
3
.40 (m, 1H), 4.02 (dd, J = 2.0, 10.8 Hz, 1H), 4.03 (s, 3H), 4.33 (dd, J = 3.2, 10.8 Hz, 1H),
.38 (d, J = 2.0 Hz, 1H), 6.58 (d, J = 2.4 Hz, 1H), 7.23-7.26 (m, 1H), 7.31 (dd, J = 8.0, 8.0
6
1
3
Hz, 1H), 7.82 (dd, J = 1.6, 8.0 Hz, 1H), 12.83 (s, 1H); C-NMR (CDCl , 100 MHz) 44.8,
3
4
1
9.9, 56.7, 69.5, 93.5, 98.2, 104.4, 116.0, 117.0, 121.7, 123.9, 146.5, 148.5, 157.7, 163.6,
65.6, 181.1 ppm.
5
.4. General method for synthesis of C-1-O-alkyl or arylalkylated C-3-(oxiran-2-
ylmethoxy) analogues
A mixture of compound 3 or 4, R-X (3 equiv.) and Cs CO (3 equiv.) in acetone/DMF (10
2
3
mL/10 mL) was stirred at proper temperature (25-80 °C) for 20 h. The reaction was quenched
with water (30 mL) and extracted with ethyl acetate (× 3). The organic layer was collected
and washed with brine, and then dried over anhydrous MgSO . Solvent was removed under
4
reduced pressure and residue was purified by silica gel column chromatography.
5
.4.1. 1-Ethoxy-3-(oxiran-2-ylmethoxy)-9H-xanthen-9-one (5)
Following the general method, compound 3 (0.21 g, 0.73 mmol), iodoethane (0.35 g, 2.22
mmol) and Cs CO (0.52 g, 1.59 mmol) in DMF (20 mL) were used at room temperature. The
2
3
purification was conducted with eluent (ethyl acetate/n-hexane = 1:3) to give compound 5
(
0.17 g, 75.2%) as a white solid. m.p. 164 -166 °C; R 0.33 (eluent: ethyl acetate/n-hexane =
f
1
1
:1); HPLC: R 3.71 min (condition A, purity: 99.9%). H-NMR (CDCl , 400 MHz) δ 1.59 (t,
T
3
J = 2.8 Hz, 3H), 2.86 (q, J = 2.4 Hz, 1H), 2.96 (t, J = 4.4 Hz, 1H), 3.40 (m, 1H), 4.02 (dd, J =
8
2
1
1
.0, 11.2 Hz, 1H), 4.17 (dd, J = 2.0, 6.8 Hz, 2H), 4.36 (dd, J = 2.4, 10.4 Hz, 1H), 6.40 (d, J =
.4 Hz, 1H), 6.50 (d, J = 2.0 Hz, 1H), 7.32 (ddd, J = 1.2, 7.2, 8.0 Hz, 1H), 7.60 (d, J = 7.6 Hz,
1
3
H), 7.63 (ddd, J = 1.6, 7.2, 8.4 Hz, 1H), 8.28 (dd, J = 2.4, 8.0 Hz, 1H); C-NMR (CDCl ,
3
00 MHz) 14.8, 44.8, 50.0, 65.3, 69.4, 93.6, 96.4, 108.0, 117.2, 123.4, 124.0, 127.0, 133.9,

ACCEPTED MANUSCRIPT
1
55.2, 160.0, 161.8, 163.8, 175.6 ppm.
5
.4.2. 1-Isopropoxy-3-(oxiran-2-ylmethoxy)-9H-xanthen-9-one (6)
Following the general method, compound 3 (0.20 g, 0.71 mmol), 2- iodopropane (0.17 g,
.03 mmol) and Cs CO (0.52 g, 1.60 mmol) in DMF (20 mL) were used at 50 °C. The
1
2
3
purification was conducted with eluent (ethyl acetate/n-hexane = 1:3) to give compound 6
(
0.13 g, 55.6%) as a white solid. m.p. 132-134 °C; R 0.33 (eluent: ethyl acetate/n-hexane =
f
1
1
:1); HPLC: R 7.67 min (condition A, purity: 95.1%); H-NMR (CDCl , 400 MHz) δ 1.49 (d,
T
3
J = 6.0 Hz, 6H), 2.80 (dd, J = 4.2, 5.2 Hz, 1H), 2.96 (dd, J = 4.0, 4.4 Hz, 1H), 3.39-3.42 (m,
1
1
1
1
H), 4.01 (dd, J = 6.0, 11.2 Hz, 1H), 4.36 (dd, J = 2.8, 11.2 Hz, 1H), 4.66 (heptet, J = 2.0 Hz,
H), 6.41 (d, J = 2.4 Hz, 1H), 7.31 (ddd, J = 1.2, 7.6, 8.0 Hz, 1H), 7.35 (dd, J = 0.8, 8.4 Hz,
1
3
H); C-NMR (CDCl , 100 MHz) 22.1, 44.8, 50.0, 69.4, 42.3, 93.6, 98.2, 108.1, 117.1,
3
23.4, 124.0, 127.0, 133.8, 155.2, 160.0, 160.9, 163.7, 175.5 ppm.
5
.4.2. 1-Butoxy-3-(oxiran-2-ylmethoxy)-9H-xanthen-9-one (7)
Following the general method, compound 3 (0.20 g, 0.7 2mmol), 1-iodobutane (0.36 g, 2.15
mmol) and K CO (0.36 g, 2.15 mmol) were used at 80 °C. The purification was conducted
2
3
with eluent (ethyl acetate/n-hexane = 1:3) to give compound 7 (0.09 g, 37.5%) as a white
solid. m.p. 124-126 °C; R 0.49 (eluent: ethyl acetate/n-hexane = 1:1); HPLC: R 11.16 min
f
T
1
(
condition A, purity: 96.3%); H-NMR (CDCl , 400 MHz) δ 1.02 (t, J = 7.2 Hz, 3H), 1.60-
3
1
3
6
2
3
.66 (m, 2H), 1.91-1.98 (m, 2H), 2.79 (dd, J = 2.4, 4.8 Hz, 1H), 2.96 (t, J = 4.0 Hz, 1H),
.38-3.42 (m, 1H), 4.01 (dd, J = 7.0, 10.4 Hz, 1H), 4.09 (t, J = 6.4 Hz, 2H), 4.35 (dd, J = 2.8,
.8 Hz, 1H), 6.38 (d, J = 2.4 Hz, 1H), 6.47 (d, J = 2.4 Hz, 1H), 7.33 (m, 2H), 7.61 (ddd, J =
1
3
.0, 4.0, 7.2 Hz, 1H), 8.28 (dd, J = 2.0, 8.0 Hz, 1H); C-NMR (CDCl , 100 MHz) 14.1, 19.5,
3
1.2, 44.8, 50.0, 69.3, 69.4, 93.4, 96.3, 108.0, 117.2, 123.4, 124.0, 127.0, 133.8, 155.2, 159.9,

ACCEPTED MANUSCRIPT
1
62.0, 163.7, 175.5 ppm.
5
.4.3. 3-(Oxiran-2-ylmethoxy)-1-(pentyloxy)-9H-xanthen-9-one (8)
Following the general method, compound 3 (0.20 g, 0.70 mmol), 1-iodopentane (0.43 g, 2.15
mmol) and Cs CO (0.48 g, 1.48 mmol) in DMF (20 mL) were used at room temperature. The
2
3
purification was conducted with eluent (ethyl acetate/n-hexane = 1:3) to give compound 8
(
0.13 g, 53.8%) as a white solid. m.p. 120-122 °C; R 0.63 (eluent: ethyl acetate/n-hexane =
f
1
1
:1); HPLC: R 13.93 min (condition A, purity: 99.5%); H-NMR (CDCl , 400 MHz) δ 0.96
T
3
(t, J = 7.2 Hz, 3H), 1.39-1.48 (m, J = 3.2 Hz, 2H), 1.52-1.58 (m, 2H), 1.94-2.01 (m, J = 7.2
Hz, 2H), 2.80 (dd, J = 2.4, 5.6 Hz, 1H), 2.96 (t, J = 4.4 Hz, 1H), 3.38-3.42 (m, 1H), 4.00 (dd,
J = 1.6, 6.4 Hz, 1H), 4.08 (t, J = 6.8 Hz, 2H), 4.36 (dd, J = 2.4, 6.4 Hz, 1H), 6.39 (d, J = 2.4
Hz, 1H), 6.48 (d, J = 2.4 Hz, 1H), 7.33-7.36 (m, 2H), 7.62 (ddd, J = 1.6, 7.2, 8.8 Hz, 1H),
1
3
8
6
1
.28 (dd, J = 2.4, 8.0 Hz, 1H); C-NMR (CDCl , 100 MHz) 14.3. 22.7, 28.3, 28.9, 44.8, 50.0,
3
9.4, 69.7, 93.5, 96.4, 108.0, 117.2, 123.4, 124.0, 127.0, 133.8, 155.2, 159.9, 162.0, 163.8,
75.5 ppm.
5
.4.4. 1-Benzyloxy-3-(oxiran-2-ylmethoxy)-9H-xanthen-9-one (9)
Following the general method, compound 3 (0.20 g, 0.71 mmol), benzylbromide (0.24 g, 1.43
mmol) and K CO (0.24 g, 1.74 mmol) were used at 80 °C (4 h). The purification was
2
3
conducted with eluent (ethyl acetate/n-hexane = 1:2) to give compound 9 (0.17 g, 63.7%) as a
white solid. m.p. 194-196 °C; R 0.59 (eluent: ethyl acetate/n-hexane = 1:1); HPLC: R 11.27
f
T
1
min (condition A, purity: 98.4%); H-NMR (CDCl , 400 MHz) δ 2.78 (dd, J = 2.4, 4.4 Hz,
3
1
H), 2.95 (t, J = 4.4 Hz, 1H), 3.37-3.40 (m, 1H), 3.99 (dd, J = 5.6, 10.2 Hz, 1H), 4.34 (dd, J =
.8, 11.2 Hz, 1H), 5.27 (s, 2H), 6.46 (d, J = 2.4 Hz, 1H), 6.51 (d, J = 2.4 Hz, 1H), 7.31-7.45
2
1
3
(
m, 5H), 7.61-7.66 (m, 3H), 8.31 (dd, J = 2.0, 8.0 Hz, 1H); C-NMR (CDCl , 100 MHz) 44.8,
3

ACCEPTED MANUSCRIPT
4
1
9.9, 69.4, 71.0, 94.1, 97.2, 108.3, 117.2, 123.4, 124.1, 126.9, 127.0, 128.0, 128,9, 134.0,
36.5, 155.2, 159.9, 161.1, 163.7, 175.5 ppm.
5
.4.5. 1-(3-chlorobenzyloxy)-3-(oxiran-2-ylmethoxy)-9H-xanthen-9-one (10)
Following the general method, compound 3 (0.17 g, 0.59 mmol), 3-chlorobenzylchloride
0.31 g, 1.52 mmol) and K CO (0.26 g, 1.87 mmol) were used at 80 °C (20 h). The
(
2
3
purification was conducted with eluent (ethyl acetate/n-hexane = 1:3) to give compound 10
(
0.15 g, 61.6%) as a white solid. m.p. 170-172 °C; R 0.62 (eluent: ethyl acetate/n-hexane =
f
1
1
:1); HPLC: R 4.13 min (condition A, purity: 99.6%); H-NMR (CDCl , 400 MHz) δ 2.78
T
3
(
dd, J = 2.4, 4.8 Hz, 1H), 2.95 (dd, J = 4.0, 4.4 Hz, 1H), 3.37-3.40 (m, 1H), 3.98 (dd, J = 7.0,
1.2 Hz, 1H), 4.35 (dd, J = 2.8, 10.8 Hz, 1H), 5.22 (s, 2H), 6.41 (d, J = 2.0 Hz, 1H), 6.52 (d,
J = 2.4 Hz, 1H), 7.28-7.39 (m, 4H), 7.60-7.66 (m, 3H), 7.64 (ddd, J = 1.6, 7.2, 7.2 Hz, 1H),
1
1
3
8
1
1
.31 (dd, J = 1.6, 8.0 Hz, 1H); C-NMR (CDCl , 100 MHz) 44.8, 50.0, 69.5, 70.2, 94.3, 97.3,
3
08.3, 117.2, 123.3, 124.1, 125.1, 126.9, 127.0, 128.2, 130.3, 134.0, 134.7, 138.6, 155.2,
59.9, 160.8, 169.7, 175.5 ppm.
5
.4.6. 1-(3-Methoxybenzyloxy)-3-(oxiran-2-ylmethoxy)-9H-xanthen-9-one (11)
Following the general method, compound 3 (0.20 g, 0.72 mmol), 3-methoxybenzylchloride
0.32 g, 2.07 mmol) and K CO (0.35 g, 2.54 mmol) were used at 80 °C. The purification was
(
2
3
conducted with eluent (ethyl acetate/n-hexane = 1:2) to give compound 11 (0.11 g, 38.4%) as
a whites solid. m.p. 124-126 °C; R 0.49 (eluent: ethyl acetate/n-hexane = 1:1); HPLC: R
f
T
1
1
1.50 min (condition A, purity: 96.7%); H-NMR (CDCl , 400 MHz) δ 2.78 (dd, J = 2.8, 4.8
3
Hz, 1H), 2.95 (t, J = 4.8 Hz, 1H), 3.36-3.40 (m, 1H), 3.87 (s, 3H), 3.99 (dd, J = 7.0, 11.2 Hz,
H), 4.33 (dd, J = 2.8, 12.8 Hz, 1H), 5.25 (s, 2H), 6.44 (d, J = 2.4 Hz, 1H), 6.51 (d, J = 2.4
Hz, 1H), 6.85 (dd, J = 2.0, 8.0 Hz, 1H), 7.19-7.40 (m, 5H), 7.63 (ddd, J = 2.0, 4.0, 11.2 Hz,
1

ACCEPTED MANUSCRIPT
1
3
1
9
1
H), 8.31 (dd, J = 1.6, 8.0 Hz, 1H); C-NMR (CDCl , 100 MHz) 44.8, 49.9, 55.6, 69.4, 70.9,
3
4.1, 97.2, 108.3, 112.2, 123.9, 127.2, 119.0, 123.4, 124.0, 127.2, 129.9, 133.9, 138.2, 155.2,
59.9, 160.2, 161.0, 163.7, 175.4 ppm.
5
.4.7. 1-(4-Methoxybenzyloxy)-3-(oxiran-2-ylmethoxy)-9H-xanthen-9-one (12)
Following the general method, compound 3 (0.32 g, 1.13 mmol), 4-methoxybenzylchloride
0.32 g, 2.06 mmol) and K CO (0.42 g, 3.01 mmol) were used at 80 °C. The purification was
(
2
3
conducted with eluent (ethyl acetate/n-hexane = 1:2) to give compound 12 (0.03 g, 5.6%) as a
white solid. m.p. 130-132 °C; R 0.55 (eluent: ethyl acetate/n-hexane = 1:1); HPLC: R 3.77
f
T
1
min (condition A, purity: 99.3%); H-NMR (CDCl ,400 MHz) δ 2.78 (dd, J = 2.4, 4.8 Hz,
3
1
4
1
7
H), 2.95 (t, J = 4.8 Hz, 1H), 3.37-3.41 (m, 1H), 3.82 (s, 3H), 3.99 (dd, J = 2.0, 11.2 Hz, 1H),
.34 (dd, J = 2.8, 11.2 Hz, 1H), 5.20 (s, 2H), 6.45 (d, J = 2.4 Hz, 1H), 6.50 (d, J = 2.4 Hz,
H), 6.94-6.98 (m, 2H), 7.32 (ddd, J = 1.2, 3.2, 8.8 Hz, 1H), 7.36 (d, J = 8.0 Hz, 1H), 7.53-
1
3
.57 (m, 2H), 7.63 (ddd, J = 1.6, 4.0, 11.6 Hz, 1H), 8.30 (dd, J = 1.6, 8.0 Hz, 1H); C-NMR
CDCl , 100 MHz) 44.8, 50.0, 55.5, 69.4, 70.9, 94.0, 97.3, 114.3, 117.2, 123.4, 124.0, 127.0,
(
3
1
28.6, 133.9, 155.2, 159.5, 159.9, 161.2, 163.7, 175.5 ppm.
5
.4.8. 3-(Oxiran-2-ylmethoxy)-1-(3-(trifluoromethyl)benzyloxy)-9H-xanthen-9-one (13)
Following the general method, compound
3
(0.21 g, 0.73 mmol), 3-
(
trichloromethyl)benzylchloride (0.30 g, 1.46 mmol) and K CO (0.24 g, 1.74 mmol) were
2
3
used at 80 °C. The purification was conducted with eluent (ethyl acetate/n-hexane = 1:2) to
give compound 13 (0.23 g, 71.0%) as a white solid. m.p. 152-154 °C; R 0.59 (eluent: ethyl
f
1
acetate/n-hexane = 1:1); HPLC: R 8.62 min (condition A, purity: 96.3%); H-NMR (CDCl ,
T
3
4
00 MHz) δ 2.79 (dd, J = 2.4, 4.8 Hz, 1H), 2.96 (t, J = 4.4 Hz, 1H), 3.38-3.42 (m, 1H), 4.00
(dd, J = 6.4, 11.2 Hz, 1H), 4.37 (dd, J = 2.8, 11.2 Hz, 1H), 5.29 (s, 2H), 6.46 (d, J = 2.0 Hz,

ACCEPTED MANUSCRIPT
1
1
5
1
H), 6.56 (d, J = 2.4 Hz, 1H), 7.36 (m, 2H), 7.65 (ddd, J = 2.0, 7.2, 11.2 Hz, 1H), 7.84 (s,
1
3
H), 8.00-8.02 (m, 1H), 8.32 (dd, J = 2.0, 8.0 Hz, 1H); C-NMR (CDCl , 100 MHz) 44.8,
3
0.0, 69.5, 70.3, 94.5, 97.3, 108.3, 117.3, 123.3, 123.6, 124.1, 124.8, 127.0, 129.6, 130.5,
30.9, 134.1, 137.6, 155.2, 159.9, 160.7, 163.7, 175.4 ppm.
5
.4.8. 1-(3-Chlorophenethoxy)-3-(oxiran-2-ylmethoxy)-9H-xanthen-9-one (14)
Following the general method, compound 3 (0.19 g, 0.06 mmol), 3-chloro-1-phenethyl
bromide (0.30 g, 1.37 mmol) and K CO (0.26 g, 1.85 mmol) were used at 80 °C. The
2
3
purification was conducted with eluent (ethyl acetate/n-hexane = 1:3) to give compound 14
(
0.04 g, 15.4 %) as a white solid. m.p. 146-148 °C; R 0.63 (eluent: ethyl acetate/n-hexane =
f
1
1
:1); HPLC: R 4.05 min (condition A, purity: 98.2%); H-NMR (CDCl , 400 MHz) δ 2.78
T
3
(
dd, J = 2.4, 4.8 Hz, 1H), 2.95 (t, J = 4.4 Hz, 1H), 3.28 (t, J = 7.2 Hz, 2H), 3.36-3.40 (m, 1H),
.00 (dd, J = 7.0, 11.2 Hz, 1H), 4.25 (t, J = 7.2 Hz, 2H), 4.35 (dd, J = 2.8, 11.2 Hz, 1H), 6.35
d, J = 2.4 Hz, 1H), 6.51 (d, J = 2.4 Hz, 1H), 7.20-7.38 (m, 5H), 7.43 (dd, J = 2.0, 2.0 Hz,
4
(
1
3
1
1
1
H), 7.64 (ddd, J = 1.6, 7.2, 8.8 Hz, 1H), 8.31 (dd, J = 2.0, 8.0 Hz, 1H); C-NMR (CDCl ,
3
00 MHz) 35.5, 44.8, 50.0, 69.4, 70.1, 94.0, 96.6, 108.1, 117.2, 123.4, 124.9, 127.0, 127.9,
29.6, 130.0, 133.9, 134.4, 140.3, 155.2, 159.2, 161.4, 163.7, 175.3, 175.4 ppm.
5
.4.9. 1-(4-Chlorophenethoxy)-3-(oxiran-2-ylmethoxy)-9H-xanthen-9-one (15)
Following the general method, compound 3 (0.21 g, 0.72 mmol), 4- chloro-1-phenethyl
bromide (0.30 g, 1.37 mmol) and K CO (0.26 g, 1.85 mmol) were used at 80 °C. The
2
3
purification was conducted with eluent (ethyl acetate/ n-hexane = 1:3) to give compound 15
(
0.05 g, 16.5%) as a white solid. m.p. 132-134 °C; R 0.63 (eluent: ethyl acetate/n-hexane =
f
1
1
:1); HPLC: R 4.10 min (condition A, purity: 98.8%); H-NMR (CDCl , 400 MHz) δ 2.77
T
3
(dd, J = 2.4, 4.8 Hz, 1H), 2.95 (t, J = 4.8 Hz, 1H), 3.26 (t, J = 6.8 Hz, 2H), 3.36-3.40 (m, 1H),

ACCEPTED MANUSCRIPT
3
7
.98 (dd, J = 2.0, 11.2 Hz, 1H), 4.23 (t, J = 7.2 Hz, 2H), 4.34 (dd, J = 2.4, 10.8 Hz, 1H), 7.26-
1
3
.42 (m, 6H), 7.63 (ddd, J = 1.6, 6.8, 8.0 Hz, 1H), 8.30 (dd, J = 1.2, 2.0 Hz, 1H); C-NMR
(
CDCl , 100 MHz) 35.2, 44.8, 49.9, 69.4, 70.3, 93.9, 96.5, 108.2,, 117.2, 123.3, 124.1, 126.9,
3
1
28.8, 131.0, 132.7, 133.9, 136.9, 155.2, 159.9, 161.4, 163.7, 175.4 ppm.
5
.4.10. 1-Ethoxy-5-methoxy-3-(oxiran-2-ylmethoxy)-9H-xanthen-9-one (16)
Following the general method, compound 4 (0.17 g, 0.53 mmol), iodoethane (0.35 g, 2.03
mmol) and Cs CO (0.42 g, 1.30 mmol) in DMF (20 mL) were used at room temperature. The
2
3
purification was conducted with eluent (ethyl acetate/n-hexane = 1:2) to give compound 16
(
0.12 g, 66.9%) as a white solid. m.p. 150-152 °C; R 0.23 (eluent: ethyl acetate/n-hexane =
f
1
1
:1); HPLC: R 5.20 min (condition A, purity: 99.9%); H-NMR (CDCl , 400 MHz) δ 1.59 (t,
T
3
J = 2.8 Hz, 3H), 2.80 (dd, J = 2.4, 4.4 Hz, 1H), 2.95 (t, J = 4.4 Hz, 1H), 3.38-3.42 (m, 1H),
.00 (dd, J = 8.5, 11.2 Hz, 1H), 4.01 (s, 3H), 4.17 (q, J = 7.2 Hz, 2H), 4.35 (dd, J = 2.8, 10.8
Hz, 1H), 6.40 (d, J = 2.0, 8.0 Hz, 1H), 7.24 (dd, J = 7.6, 7.6 Hz, 1H), 7.86 (dd, J = 2.0, 8.0 Hz,
4
1
3
1
1
H); C-NMR (CDCl , 100 MHz) 14.8, 44.8, 49.9, 56.6, 65.2, 69.4, 93.6, 96.8, 107.9, 114.7,
3
18.0, 123.5, 124.3, 148.2, 159.7, 161.6, 163.7, 175.5 ppm.
5
.4.11. 1-Isopropoxy-5-methoxy-3-(oxiran-2-ylmethoxy)-9H-xanthen-9-one (17)
Following the general method, compound 4 (0.20 g, 0.64 mmol), 2- iodopropane (0.17 g,
.03 mmol) and Cs CO (0.51 g, 1.55 mmol) were used at room temperature. The purification
1
2
3
was conducted with eluent (ethyl acetate/n-hexane = 1:3) to give compound 17 (0.14 g,
6
4.8%) as a white solid. m.p. 162-164 °C; R 0.33 (eluent: ethyl acetate/n-hexane = 1:1);
f
1
HPLC: R 4.07 min (condition A, purity: 97.8%); H-NMR (CDCl , 400 MHz) δ 1.49 (d, J =
T
3
7
.0 Hz, 6H), 2.78 (dd, J = 2.4, 4.8 Hz, 1H), 3.38-3.42 (m, 1H), 4.00 (dd, J = 5.6, 7.2 Hz, 1H),
.01 (s, 3H), 4.34 (dd, J = 3.2, 11.2 Hz, 1H), 4.65 (heptet, J = 2.4 Hz, 1H), 6.41 (d, J = 2.4 Hz,
4

ACCEPTED MANUSCRIPT
1
7
9
H), 6.58 (d, J = 2.4 Hz, 1H), 7.15 (dd, J = 1.2, 2.0 Hz, 1H), 7.24 (dd, J = 4.0, 8.0 Hz, 1H),
13
.58 (dd, J = 2.0, 8.0 Hz, 1H); C-NMR (CDCl , 100 MHz) 22.1, 44.8, 49.9, 56.6, 69.4, 72.2,
3
3.6, 98.5, 108.6, 114.7, 118.0, 123.5, 124.4, 145.4, 148.1, 159.8, 160.7, 163.6, 175.3 ppm.
5
.4.12. 1-Butoxy-5-methoxy-3-(oxiran-2-ylmethoxy)-9H-xanthen-9-one (18)
Following the general method, compound 4 (0.27 g, 0.86 mmol), 1-iodobutane (0.49 g, 2.64
mmol) and K CO (0.39 g, 2.79 mmol) were used at 80 °C. The purification was conducted
2
3
with eluent (ethyl acetate/n-hexane = 1:2) to give compound 18 (0.01 g, 31.1 %) as a white
solid. m.p. 162-164 °C; R 0.44 (eluent: ethyl acetate/n-hexane = 1:1); HPLC: R 3.85 min
f
T
1
(
condition A, purity: 99.9%); H-NMR (CDCl , 400 MHz) δ 1.01 (t, J = 3.2 Hz, 3H), 1.58-
3
1
.67 (m, J = 3.6 Hz, 2H), 1.91-1.98 (m, J = 6.4 Hz, 2H), 2.78 (dd, J = 2.4, 4.0 Hz, 1H), 2.94
t, J = 4.4 Hz, 1H), 3.37-3.41 (m, 1H), 3.99 (dd, J = 6.0, 10.8 Hz, 1H), 4.00 (s, 3H), 4.34 (dd,
J = 2.8, 10.8 Hz, 1H), 6.39 (d, J = 2.4 Hz, 1H), 6.58 (d, J = 2.0 Hz, 1H), 7.14 (dd, J = 5.6, 8.0
(
1
3
Hz, 1H), 7.24-7.26 (m, 1H), 7.86 (dd, J = 1.6, 8.0 Hz, 1H); C-NMR (CDCl , 100 MHz)
3
1
1
4.1, 19.5, 31.2, 44.8, 49.9, 56.6, 69.3, 69.4, 93.5, 96.7, 107.9, 114.7, 118.0, 123.5, 124.3,
45.4, 148.1, 159.7, 161.8, 163.7, 175.4 ppm.
5
.4.13. 5-Methoxy-3-(oxiran-2-ylmethoxy)-1-(pentyloxy)-9H-xanthen-9-one (19)
Following the general method, compound 4 (0.15 g, 0.48 mmol), 1-iodopentane (0.43 g, 2.14
mmol) and Cs CO (0.43 g, 1.31 mmol) in DMF (20 mL) were used at room temperature.
2
3
The purification was conducted with eluent (ethyl acetate/n-hexane = 1:2) to give compound
1
9 (0.10 g, 52.7%) as a white solid. m.p. 144-146 °C; R 0.45 (eluent: ethyl acetate/n-hexane
f
1
=
1:1); HPLC: R 12.83 min (condition A, purity: 97.6%); H-NMR (CDCl , 400 MHz) δ
T
3
0
.96 (t, J = 7.2 Hz, 3H), 1.40-1.46 (m, 2H), 1.52-1.59 (m, 2H), 1.94-2.01 (m, 2H), 2.78 (dd, J
2.4, 5.6 Hz, 1H), 2.95 (t, J = 4.4 Hz, 1H), 3.39-3.41 (m, 1H), 4.00 (dd, J = 2.4, 7.5 Hz, 1H),
=

ACCEPTED MANUSCRIPT
4
.00 (s, 3H), 4.07 (t, J = 6.8 Hz, 1H), 6.40 (d, J = 2.4 Hz, 1H), 6.58 (d, J = 2.4 Hz, 1H), 7.15
1
3
(
dd, J = 1.6, 8.0 Hz, 1H), 7.22-7.26 (m, 2H), 7.86 (dd, J = 1.6, 8.0 Hz, 1H); C-NMR (CDCl ,
3
1
00 MHz) 14.2, 22.7, 28.3, 28.9, 44.8, 49.9, 56.6, 69.4, 69.7, 93.5, 96.7, 107.9, 114.7, 118.0,
23.5, 124.3, 14.4, 148.1, 159.7, 161.8, 163.7, 175.4 ppm.
1
5
.4.14. 1-Benzyloxy-5-methoxy-3-oxiranylmethoxy-xanthen-9-one (20)
Following the general method, compound 4 (0.22 g, 0.76 mmol), benzylbromide (0.14 g, 0.81
mmol) and K CO (0.33 g, 2.40 mmol) were used. The purification was conducted with
2
3
eluent (ethyl acetate/n-hexane = 1:2) to give compound 20 (0.03 g, 12.1%) as a white solid.
m.p. 192-194 °C; R 0.44 (eluent: ethyl acetate/n-hexane = 1:1); HPLC: R 11.20 min
f
T
1
(
condition A, purity: 95.2%); H-NMR (CDCl , 400 MHz) δ 2.77 (dd, J = 2.8, 4.8 Hz, 1H),
3
2
.94 (t, J = 4.4 Hz, 1H), 3.36-3.40 (m, 1H), 3.99 (dd, J = 7.0, 10.8 Hz, 1H), 4.02 (s, 3H), 4.33
dd, J = 3.2, 10.8 Hz, 1H), 5.26 (s, 2H), 6.46 (d, J = 2.0 Hz, 1H), 6.62 (d, J = 2.0 Hz, 1H),
.16 (dd, J = 1.2, 8.0 Hz, 1H), 7.23-7.34 (m, 2H), 7.40-7.44 (m, 2H), 7.64 (d, J = 8.0 Hz, 2H),
(
7
7
1
1
1
3
.89 (dd, J = 2.8, 8.0 Hz, 1H); C-NMR (CDCl , 100 MHz) 49.8, 56.6, 69.4, 71.0, 94.1, 97.5,
3
08.3, 117.2, 123.4, 124.1, 126.9, 127.0, 128.0, 128,9, 134.0, 136.5, 155.2, 159.9, 161.1,
63.7, 175.5 ppm.
5
.4.15. 1-(3-Chlorobenzyloxy)-5-methoxy-3-(oxiran-2-ylmethoxy)-9H-xanthen-9-one (21)
Following the general method, Compound 4 (0.21 g, 0.65 mmol), 3-chlorobenzylchloride
0.47 g, 2.28 mmol) and K CO (0.33 g, 2.37 mmol) were used at 80 °C. The purification was
(
2
3
conducted with eluent (ethyl acetate/n-hexane = 1:1) to give compound 21 (0.14 g, 47.3%) as
a white solid. m.p. 170-172 °C; R 0.51 (eluent: ethyl acetate/n-hexane=1:1); HPLC: R 13.71
f
T
1
min (condition A, purity: 99.9%); H-NMR (CDCl , 400 MHz) δ 2.77 (dd, J = 2.4, 4.8 Hz,
3
1
H), 2.95 (t, J = 4.4 Hz, 1H), 2.98 (dd, J = 7.0, 11.2 Hz, 1H), 3.37-3.41 (m, 1H), 4.02 (s, 3H),

ACCEPTED MANUSCRIPT
4
1
2
1
1
.34 (dd, J = 2.4, 10.8 Hz, 1H), 5.22 (s, 2H), 6.43 (d, J = 2.4 Hz, 1H), 6.63 (d, J = 2.4 Hz,
H), 7.17 (dd, J = 1.2, 8.0 Hz, 1H), 7.24-7.40 (m, 4H), 7.60-7.62 (m, 2H), 7.89 (dd, J = 1.6,
1
3
.0 Hz, 1H); C-NMR (CDCl , 100 MHz) 44.3, 49.6, 56.3, 69.3, 69.8, 94.1, 97.3, 107.6,
3
14.6, 117.4, 123.3, 123.8, 124.8, 126.6, 127.8, 129.9, 134.2, 138.3, 145.1, 147.9, 159.4,
60.2, 163.4, 174.9 ppm.
5
.4.16. 5-Methoxy-1-(3-methoxybenzyloxy)-3-(oxiran-2-ylmethoxy)-9H-xanthen-9-one
(
22)
Following the general method, compound 4 (0.25 g, 0.78 mmol), 3-methoxybenzylchloride
0.38 g, 2.41 mmol) and Cs CO (0.39 g, 2.84 mmol) was used at 80 °C. The purification was
(
2
3
conducted with eluent (ethyl acetate/n-hexane = 1:2) to give compound 22 (0.07 g, 20.9%) as
a white solid. m.p. 150-151 °C; R 0.46 (eluent: ethyl acetate/n-hexane = 1:1); HPLC: R 3.68
f
T
1
min (condition A, purity: 100.0%); H-NMR (CDCl , 400 MHz) δ 2.77 (dd, J = 2.4, 4.8 Hz,
3
1
H), 2.94 (t, J = 4.8 Hz, 1H), 3.36-3.40 (m, 1H), 3.87 (s, 3H), 3.97 (dd, J = 5.6, 11.2 Hz, 1H),
.01 (s, 3H), 4.32 (dd, J = 2.8, 11.2 Hz, 1H), 5,24 (s, 2H), 6.45 (d, J = 2.4 Hz, 1H), 6.61 (d, J
4
=
2.4 Hz, 1H), 6.85 (dd, J = 2.0, 8.0 Hz, 1H), 7.16 (dd, J = 1.6, 2.0 Hz, 1H), 7.17-7.20 (m,
1
1
1
H), 7.20-7.26 (m, 2H), 7.27-7.30 (m, 1H), 7.33 (d, J = 8.0 Hz, 1H), 7.88 (dd, J = 1.6, 8.0 Hz,
1
3
H); C-NMR (CDCl , 100 MHz) 44.8, 48.9, 56.6, 69.4, 70.8, 94.1, 97.6, 108.2, 112.1,
3
13.9, 114.8, 123.5, 124.3, 129.9, 138.2, 145.5, 148.2, 159.7, 160.2, 160.9, 163.6, 175.3 ppm.
5
.4.17. 5-Methoxy-1-(4-methoxybenzyloxy)-3-(oxiran-2-ylmethoxy)-9H-xanthen-9-one
(
23)
Following the general method, compound 4 (0.21 g, 0.68 mmol), 4-methoxybenzylchloride
0.28 g, 1.77 mmol) and Cs CO (0.42 g, 1.29 mmol) was used at 60 °C. The purification was
(
2
3
conducted with eluent (ethyl acetate/n-hexane = 1:2) to give compound 23 (0.01 g, 31.1%) as

ACCEPTED MANUSCRIPT
a white solid. m.p. 102-104 °C; R 0.21 (eluent: ethyl acetate/n-hexane = 1:1); HPLC: R 10.9
f
T
1
min (condition A, purity: 96.1%); H-NMR (CDCl , 400 MHz) δ 2.75 (dd, J = 2.4, 4.8 Hz,
3
1
H), 2.92 (dd, J = 4.8, 4.8 Hz, 1H), 3.35-3.38 (m, 1H), 3.81 (s, 3H), 3.99 (s, 3H), 4.11 (dd, J
7.2, 14.4 Hz, 1H), 4.30 (dd, J = 2.4, 11.2 Hz, 1H), 5.17 (s, 2H), 6.44 (d, J = 2.4 Hz, 1H),
.58 (d, J = 2.4 Hz, 1H), 6.93-6.95 (m, 2H), 7.14 (dd, J = 1.2, 8.0 Hz, 1H), 7.23 (dd, J = 8.0,
=
6
8
1
1
1
3
.0 Hz, 1H), 7.54 (dd, J = 2.4, 7.2 Hz, 1H), 7.86 (dd, J = 1.6, 8.0 Hz, 1H); C-NMR (CDCl ,
3
00 MHz) 44.7, 49.9, 55.5, 56.6, 69.4, 70.8, 94.0, 97.5, 108.1, 114.3, 114.7, 117.9, 123.5,
24.3, 128.6, 128.8, 145.4, 148.1, 159.4, 159.6 , 161.0, 163.6, 175.3 ppm.
5
.4.18.
5-Methoxy-3-(oxiran-2-ylmethoxy)-1-(3-(trifluoromethyl)benzyloxy)-9H-
xanthen-9-one (24)
Following the general method, compound
4
(0.10 g, 0.31 mmol), 3-
(
trichloromethyl)benzylchloride (0.14 g, 0.66 mmol) and K CO (0.15 g, 1.09 mmol) were
2 3
used at 80 °C. The purification was conducted with eluent (ethyl acetate/n-hexane = 1:2) to
give compound 24 (0.07 g, 45.7%) as a white solid. m.p. 152-154 °C; R 0.47 (eluent: ethyl
f
1
acetate/n-hexane = 1:1); HPLC: R 16.47 min (condition A, purity: 95.1%); H-NMR (CDCl ,
T
3
4
00 MHz) δ 2.77 (dd, J = 2.8, 4.8 Hz, 1H), 2.95 (t, J = 4.4 Hz, 1H), 3.38-3.41 (m, 1H), 3.97
dd, J = 2.8, 6.0 Hz, 1H), 4.01 (s, 3H), 4.35 (dd, J = 2.8, 11.2 Hz, 1H), 5.27 (s, 2H), 6.45 (d, J
2.4 Hz, 1H), 6.64 (d, J = 2.4 Hz, 1H), 7.17 (dd, J = 2.0, 8.0 Hz, 1H), 7.26 (t, J = 8.0 Hz,
(
=
13
1
H), 7.59-7.60 (m, 2H), 7.84 (s, 1H), 7.88 (dd, J = 1.6, 8.0 Hz, 1H); C-NMR (CDCl , 100
3
MHz) 44.7, 49.9, 56.6, 69.5, 70.3, 94.5, 97.6, 108.1, 114.9, 118.0, 123.6, 124.3, 124.8, 129.6,
1
30.4, 137.6, 145.5, 148.2, 159.7, 160.6, 163.6, 175.3 ppm.
5
.4.19. 1-(3-Chlorophenethoxy)-5-methoxy-3-(oxiran-2-ylmethoxy)-9H-xanthen-9-one
(25)

ACCEPTED MANUSCRIPT
Following the general method, compound 4 (0.20 g, 0.65 mmol), 3-chloro-1-
phenethylbromide (0.30 g, 1.37 mmol) and K CO (0.26 g, 1.88 mmol) were used at 80 °C.
2
3
The purification was conducted with eluent (ethyl acetate/n-hexane = 1:2) to give compound
2
5 (0.11 g, 18.3%) as a white solid. m.p. 148-150 °C; R 0.48 (eluent: ethyl acetate/n-hexane
f
1
=
1:1); HPLC: R 14.15 min (condition A, purity: 95.3%); H-NMR (CDCl , 400 MHz) δ
T
3
2
1
1
1
8
1
1
.76 (dd, J = 2.4, 4.8 Hz, 1H), 2.93 (t, J = 4.8 Hz, 1H), 3.25 (t, J = 7.2 Hz, 2H), 3.35-3.40 (m,
H), 3.96 (dd, J = 7.0, 10.8 Hz, 1H), 4.00 (s, 3H), 4.23 (t, J = 6.8 Hz, 1H), 4.31 (dd, J = 3.2,
5.2 Hz, 1H), 6.33 (d, J = 2.0 Hz, 1H), 6.58 (d, J = 2.0 Hz, 1H), 7.17 (dd, J = 2.0, 8.0 Hz,
H), 7.20-7.22 (m, 1H), 7.26 (dd, J = 8.0, 8.0 Hz, 3H), 7.34-7.43 (m, 2H), 7.87 (dd, J = 2.0,
1
3
.0 Hz, 1H); C-NMR (CDCl , 100 MHz) 35.5, 44.8, 49.9, 56.6, 69.4, 70.1, 94.0, 97.0, 108.0,
3
14.8, 118.0, 123.6, 124.3, 127.0, 127.9, 129.6, 130.0, 134.4, 140.3, 145.5, 149.2, 159.7,
61.2, 163.7, 175.3 ppm.
5
.4.20. 1-(4-Chlorophenethoxy)-5-methoxy-3-(oxiran-2-ylmethoxy)-9H-xanthen-9-one
(26)
Following the general method, compound 4 (0.20 g, 0.65 mmol), 4-chloro-1-
phenethylbromide (0.30 g, 1.37 mmol) and K CO (0.26 g, 1.88 mmol) were used at 80 °C.
2
3
The purification was conducted with eluent (ethyl acetate/n-hexane = 1:2) to give compound
2
6 (0.09 g, 29.9%) as a white solid. m.p. 206-208 °C; R 0.55 (eluent: ethyl acetate/n-hexane
f
1
=
1:1); HPLC: R 14.51 min (condition A, purity: 95.0%); H-NMR (CDCl , 400 MHz) δ
T
3
2
.77 (dd, J = 2.8, 4.8 Hz, 1H), 2.94 (t, J = 4.0 Hz, 1H), 2.98 (dd, J = 2.0, 10.8 Hz, 1H), 3.25 (t,
J = 3.2 Hz, 1H), 3.36-3.40 (m, 1H), 4.02 (s, 3H), 4.22 (t, J = 2.8 Hz, 2H), 4.33 (dd, J = 2.4,
1
1
1
0.8 Hz, 1H), 6.35 (d, J = 2.4 Hz, 1H), 6.61 (d, J = 2.4 Hz, 1H), 7.16 (dd, J = 1.2, 8.0 Hz,
1
3
H), 7.24-7.31 (m, 4H), 7.39-7.41 (m, 2H), 7.88 (dd, J = 1.2, 8.0 Hz, 1H); C-NMR (CDCl ,
3
00 MHz) 34.6, 39.7, 44.1, 49.4, 56.1, 69.0, 69.7, 93.6, 96.4, 114.4, 117.2, 123.1, 123.6,

ACCEPTED MANUSCRIPT
1
28.2, 130.6, 131.9, 136.6, 144.9, 147.7, 159.1, 160.7, 163.3, 174.7 ppm.
5
.5. General method for n-butylamine mediated Epoxide Ring Opened compounds
Group 1 compound and n-butylamine (10 equiv.) in MeOH (10 mL) was stirred at 50 °C
under N (20 h), and then cooled to room temperature. Solvent was evaporated and H O was
2
2
added. The aqueous mixture was extract with ethyl acetate (× 3). The organic layer was
collected and washed with brine, and then dried over anhydrous MgSO . Solvent was
4
removed under reduced pressure and residue was purified by silica gel column
chromatography.
5
.5.1. 3-(3-Butylamino-2-hydroxypropoxy)-1-ethoxy-9H-xanthen-9-one (27)
Following the general method, compound 5 (0.15 g, 0.49 mmol) and n-butylamine (0.18 g,
2
1
9
1
3
.43 mmol) were used to give compound 27 (0.05 g, 24.4%) as a pale orange solid. m.p. 164-
66 °C; R 0.33 (eluent: MeOH:CH Cl = 1:5); HPLC: R 4.11 min (condition B, purity:
f
2
2
T
1
8.7%); H-NMR (CDCl , 400 MHz) δ 0.96 (t, J = 7.2 Hz, 3H), 1.43 (hexet, J = 3.6 Hz, 2H),
3
.57 (t, J = 7.2 Hz, 3H), 1.87 (quint, J = 8.0 Hz, 2H), 3.04-3.08 (m, 2H), 3.15-3.20 (m, 1H),
.30 (dd, J = 2.4, 12.8 Hz, 1H), 4.06 (dd, J = 7.5, 9.6 Hz, 1H), 4.12-4.17 (m, 4H), 4.63-4.64
(m, 1H), 6.34 (d, J = 2.4 Hz, 1H), 6.38 (d, J = 2.4 Hz, 1H), 7.25-7.28 (m, 2H), 7.56 (ddd, J =
1
3
1
2
1
.6, 7.2, 8.0 Hz, 1H), 8.22 (dd, J = 2.0, 8.0 Hz, 1H); C-NMR (CDCl , 100 MHz) 13.8, 14.8,
3
0.2, 28.2, 49.0, 51.4, 65.3, 65.6, 69.9, 93.5, 96.2, 108.0, 117.1, 123.2, 124.0, 126.8, 133.9,
55.0, 159.8, 161.7, 163.4, 175.5 ppm.
5
.5.2. 3-(3-Butylamino-2-hydroxypropoxy)-1-isopropoxy-9H-xanthen-9-one (28)
Following the general method, compound 6 (16.3 g, 0.06 mmol) and n-butylamine (0.04 g,
.61 mmol) were used to give compound 28 (0.01 g, 49.0%) as a pale yellow solid. m.p. 180-
0

ACCEPTED MANUSCRIPT
1
9
1
1
4
7
82 °C; R 0.33 (eluent: MeOH:CH Cl = 1:5); HPLC: R 7.91 min (condition B, purity:
f
2
2
T
1
2.3%); H-NMR (CDCl , 400 MHz) δ 0.96 (t, J = 7.6 Hz, 3H), 1.40 (hexet, J = 7.6 Hz, 2H),
3
.48 (d, J = 5.6 Hz, 6H), 1.86 (quint, J = 7.6 Hz, 2H), 2.99-3.10 (m, 2H), 3.15 (dd, J = 9.6,
2.4 Hz, 1H), 3.29 (dd, J = 2.8, 12.0 Hz, 1H), 4.07 (dd, J = 5.6, 10.0 Hz, 1H), 4.15 (dd, J =
.8, 9.6 Hz, 1H), 4.60-4.68 (m, 1H), 6.28 (d, J = 2.0 Hz, 1H), 6.41 (d, J = 2.0 Hz, 1H), 7.25-
1
3
.30 (m, 2H), 7.57 (ddd, J = 1.6, 6.8, 8.4 Hz, 1H), 8.22 (dd, J = 1.6, 8.0 Hz, 1H); C-NMR
(
CDCl , 100 MHz) 13.8, 20.2, 22.1, 28.7, 49.0, 51.5, 65.9, 70.0, 72.4, 93.6, 98.0, 108.8,
3
1
17.1, 123.3, 124.0, 126.9, 133.9, 155.1, 159.9, 160.9, 163.3, 175.4 ppm.
5
.5.3. 1-Butoxy-3-(3-butylamino-2-hydroxypropoxy)-9H-xanthen-9-one (29)
Following the general method, compound 7 (0.06 g, 0.17 mmol) and n-butylamine (0.15 g,
2
.02 mmol) were used to give compound 29 (0.06 g, 90.2%) as a white solid. m.p. 80-82 °C;
1
R 0.46 (eluent: MeOH:CH Cl = 1:5); HPLC: R 2.51 min (condition B, purity: 98.0%); H-
f
2
2
T
NMR (CDCl , 400 MHz) δ 0.93 (t, J = 7.2 Hz, 3H), 1.01 (t, J = 7.6 Hz, 3H), 1.37 (hexet, J =
3
6
.8 Hz, 2H), 1.52 (quint, J = 6.8 Hz, 2H), 1.63 (hexet, J = 7.6 Hz, 2H), 1.95 (quint, J = 6.4
Hz, 2H), 2.64-2.73 (m, 4H), 2.78 (dd, J = 8.0, 12.0 Hz, 1H), 2.91 (dd, J = 4.0, 12.0 Hz, 1H),
.48 (s, 1H), 4.05-4.12 (m, 4H), 6.36 (d, J = 2.4 Hz, 1H), 6.47 (d, J = 2.4 Hz, 1H), 7.26-7.32
m, 1H), 7.35-7.35 (m, 1H), 7.61 (ddd, J = 2.0, 4.0, 12.0 Hz, 1H), 8.27 (dd, J = 1.6, 8.0 Hz,
3
(
1
3
1
7
H); C-NMR (CDCl , 100 MHz) 14.1, 14.2, 19.5, 20.5, 31.2, 32.2, 49.7, 51.7, 67.8, 69.3,
3
1.0, 93.5, 96.3, 107.9, 117.1, 123.4, 123.9, 126.9, 133.8, 155.2, 159.9, 161.9, 164.1, 175.5
ppm.
5
.5.4. 3-(3-Butylamino-2-hydroxypropoxy)-1-pentyloxy-9H-xanthen-9-one (30)
Following the general method, compound 8 (0.11 g, 0.31 mmol) and n-butylamine (0.10 g,
.42 mmol) were used to give compound 30 (0.06 g, 43.0%) as a pale yellow solid. m.p. 188-
1