Lewis Acid-Catalyzed [2+4] Cyclization of 3-Alkyl-2-vinylindoles with α,β-Unsaturated N-Sulfonyl Ketimines

doi:10.6023/cjoc202210037

Chinese Journal of Organic Chemistry ›› 2023, Vol. 43 ›› Issue (6): 2178-2188.DOI: 10.6023/cjoc202210037 Previous Articles Next Articles

Lewis酸催化下3-烷基-2-吲哚烯与α,β-不饱和N-磺酰基亚胺的[2+4]环化反应

孙李星^a, 孙婷婷^a, 王海清^a, 吴淑芳^a, 王小烨^c, 刘天雅^b^,^*(), 张宇辰^a^,^*()

a 江苏师范大学化学与材料科学学院江苏徐州 221116
b 徐州医科大学附属医院麻醉科江苏徐州 221004
c 徐州医科大学江苏省麻醉学重点实验室江苏徐州 221004

收稿日期:2022-10-29 修回日期:2022-12-10 发布日期:2022-12-28
作者简介:
^† 共同第一作者
基金资助:
国家自然科学基金(22101103); 江苏省自然科学基金(BK20201018); 江苏省高层次创新创业人才引进、徐州市科技计划(KC21021); 江苏省大学生创新(202110320041Z)

Lewis Acid-Catalyzed [2+4] Cyclization of 3-Alkyl-2-vinylindoles with α,β-Unsaturated N-Sulfonyl Ketimines

Lixing Sun^a, Tingting Sun^a, Haiqing Wang^a, Shufang Wu^a, Xiaoye Wang^c, Tianya Liu^b,*(), Yuchen Zhang^a,*()

a School of Chemistry and Materials Science, Jiangsu Normal University, Xuzhou, Jiangsu 221116
b Department of Anesthesiology, The Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu 221004
c Key Laboratory of Anesthesiology of Jiangsu Province, Xuzhou Medical University, Xuzhou, Jiangsu 221004

Received:2022-10-29 Revised:2022-12-10 Published:2022-12-28
Contact: * E-mail: zhangyc@jsnu.edu.cn; tianyaliu2004@163.com
About author:
^† These authors contributed equally to this work
Supported by:
National Natural Science Foundation of China(22101103); Natural Science Foundation of Jiangsu Province(BK20201018); High-level Innovative and Entrepreneurial Talents Introduction Plan of Jiangsu Province, the Technology Plan of Xuzhou City(KC21021); Undergraduate Students Project of Jiangsu Province(202110320041Z)

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Abstract

A Lewis acid-catalyzed [2+4] cyclization of 3-alkyl-2-vinylindoles with α,β-unsaturated N‑sulfonyl ketimines was established, and indole-containing piperidines with potential antitumor activity were synthesized in moderate to good yields (up to 95% yield) and generally excellent diastereoselectivities (up to>95:5 dr). This work has confronted the challenges in exploring the [2+4] cyclization of 3-alkyl-2-vinylindoles, which will enrich the chemistry of 3-alkyl-2-vinylindoles. In addition, this approach provides an atom-economic method for the synthesis of indole-containing piperidines.

Key words: 3-alkyl-2-vinylindole, α,β-unsaturated N-sulfonyl ketimine, [2+4] cyclization, indole derivative

Cite this article

Lixing Sun, Tingting Sun, Haiqing Wang, Shufang Wu, Xiaoye Wang, Tianya Liu, Yuchen Zhang. Lewis Acid-Catalyzed [2+4] Cyclization of 3-Alkyl-2-vinylindoles with α,β-Unsaturated N-Sulfonyl Ketimines[J]. Chinese Journal of Organic Chemistry, 2023, 43(6): 2178-2188.

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References 15

[1]	For some reviews: (a) Kochanowska-Karamyan, A. J.; Hamann, M. T. Chem. Rev. 2010, 110, 4489. doi: 10.1021/cr900211p pmid: 20380420
	(b) Peng, J.-J.; Deng, Y. Q. Chin. J. Org. Chem. 2002, 22, 71. pmid: 20380420
[2]	For some reviews: (a) Dalpozzo, R. Chem. Soc. Rev. 2015, 44, 742. doi: 10.1039/c4cs00209a pmid: 25316161
	(b) Chen, J.-B.; Jia, Y.-X. Org. Biomol. Chem. 2017, 15, 3550. doi: 10.1039/C7OB00413C pmid: 25316161
	(c) Huang, G.; Yin, B. Adv. Synth. Catal. 2019, 361, 405. doi: 10.1002/adsc.v361.3 pmid: 25316161
	(d) Li, T.-Z.; Liu, S.-J.; Tan, W.; Shi, F. Chem.-Eur. J. 2020, 26, 15779. doi: 10.1002/chem.v26.68 pmid: 25316161
	(e) Zhang, H.-H.; Shi, F. Chin. J. Org. Chem. 2022, 42, 3351. (in Chinese) doi: 10.6023/cjoc202203018 pmid: 25316161
	(张洪浩, 石枫, 有机化学, 2022, 42, 3351.) doi: 10.6023/cjoc202203018 pmid: 25316161
	For some recent examples: (f) Ma, C.; Sheng, F.-T.; Wang, H.-Q.; Deng, S.; Zhang, Y.-C.; Jiao, Y.-C.; Tan, W.; Shi, F. J. Am. Chem. Soc. 2020, 142, 15686. doi: 10.1021/jacs.0c00208 pmid: 25316161
	(g) Wu, P.; Yu, L.; Gao, C.-H.; Cheng, Q.; Deng, S.; Jiao, Y.; Tan, W.; Shi, F. Fundam. Res. 2022, DOI: 10.1016/j.fmre.2022.01.002. doi: 10.1016/j.fmre.2022.01.002 pmid: 25316161
	(h) Wang, J.-Y.; Zhang, S.; Yu, X.-Y.; Wang, Y.-H.; Wan, H.-L.; Zhang, S.; Tan, W.; Shi, F. Tetrahedron Chem. 2022, 1, 100007. doi: 10.1016/j.tchem.2022.100007 pmid: 25316161
	(i) Jiang, M.; Zhou, T.; Shi, B. Chin. J. Org. Chem. 2020, 40, 4364. (in Chinese) doi: 10.6023/cjoc202000083 pmid: 25316161
	(江梦雪, 周涛, 史炳锋, 有机化学, 2020, 40, 4364.) doi: 10.6023/cjoc202000083 pmid: 25316161
	(j) Tan, W.; Shi, F. Chem. Synth. 2022, 2, 11. doi: 10.20517/cs pmid: 25316161
[3]	For some reviews: (a) Zhang, Y.-C.; Jiang, F.; Shi, F. Acc. Chem. Res. 2020, 53, 425. doi: 10.1021/acs.accounts.9b00549
	(b) Sheng, F.-T.; Wang, J.-Y.; Tan, W.; Zhang, Y.-C.; Shi, F. Org. Chem. Front. 2020, 7, 3967. doi: 10.1039/D0QO01124J
	For some recent examples: (c) Hang, Q.-Q.; Wu, S.-F.; Yang, S.; Wang, X.; Zhong, Z.; Zhang, Y.-C.; Shi, F. Sci. China: Chem. 2022, 65, 1929.
	(d) Sheng, F.-T.; Yang, S.; Wu, S.-F.; Zhang, Y.-C.; Shi, F. Chin. J. Chem. 2022, 40, 2151. doi: 10.1002/cjoc.v40.18
[4]	For a review: Tu, M.-S.; Chen, K.-W.; Wu, P.; Zhang, Y.-C.; Liu, X.-Q.; Shi, F. Org. Chem. Front. 2021, 8, 2643. doi: 10.1039/D0QO01643H
[5]	For some recent examples: (a) Zhang, L.-L.; Zhang, J.-W.; Xiang, S.-H.; Guo, Z.; Tan, B. Org. Lett. 2018, 20, 6022. doi: 10.1021/acs.orglett.8b02361
	(b) Mei, G.-J.; Zheng, W.; Gonçalves, T. P.; Tang, X.; Huang, K.-W.; Lu, Y. iScience 2020, 23, 100873. doi: 10.1016/j.isci.2020.100873
	(c) Koay, W. L.; Mei, G.-J.; Lu, Y. Org. Chem. Front. 2021, 8, 968. doi: 10.1039/D0QO01236J
	(d) Mou, C.; Zhou, L.; Song, R.; Chai, H.; Hao, L.; Chi, Y. R. Org. Lett. 2020, 22, 2542. doi: 10.1021/acs.orglett.0c00418
[6]	C(3)-nucleophilicity dearomative reactions of 3-alkyl-2-vinylin- doles: (a) Wang, Y.; Sun, M.; Yin, L.; Shi, F. Adv. Synth. Catal. 2025, 357, 4031. doi: 10.1002/adsc.201500901
	(b) Chen, K.-W.; Wang, D.-D.; Liu, S.-J.; Wang, X.; Zhang, Y.-C.; Tian, Y.-M.; Wu, Q.; Shi, F. J. Org. Chem. 2021, 86, 10427. doi: 10.1021/acs.joc.1c01105
[7]	[2+3] cyclizations of 3-alkyl-2-vinylindoles: (a) Tan, W.; Li, X.; Gong, Y.-X.; Ge, M.-D.; Shi, F. Chem. Commun. 2014, 50, 15901. doi: 10.1039/C4CC07246D pmid: 30620204
	(b) Bera, K.; Schneider, C. Chem.-Eur. J. 2016, 22, 7074. doi: 10.1002/chem.201601020 pmid: 30620204
	(c) Yin, L.; Wang, Y.; Sun, M.; Shi, F. Adv. Synth. Catal. 2016, 358, 1093. doi: 10.1002/adsc.201501116 pmid: 30620204
	(d) Zhu, Z.-Q.; Yin, L.; Wang, Y.; Shen, Y.; Li, C.; Mei, G.-J.; Shi, F. Org. Chem. Front. 2017, 4, 57. doi: 10.1039/C6QO00446F pmid: 30620204
	(e) Kallweit, I.; Schneider, C. Org. Lett. 2019, 21, 519. doi: 10.1021/acs.orglett.8b03833 pmid: 30620204
	[2+6] cyclizations of 3-alkyl-2-vinylindoles: (f) Sarkar, R.; Kallweit, I.; Schneider, C. Org. Lett. 2022, 24, 6433. doi: 10.1021/acs.orglett.2c02548 pmid: 30620204
[8]	[2+4] Cyclizations of 3-alkyl-2-vinylindoles: (a) Dai, W.; Jiang, X.-L.; Tao, J.-Y.; Shi, F. J. Org. Chem. 2016, 81, 185. doi: 10.1021/acs.joc.5b02476
	(b) Zhao, J.-J.; Sun, S.-B.; He, S.-H.; Wu, Q.; Shi, F. Angew. Chem., Int. Ed. 2015, 54, 5460. doi: 10.1002/anie.201500215
	(c) Jiang, X.-L.; Wu, S.-F.; Wang, J.-R.; Mei, G.-J.; Shi, F. Adv. Synth. Catal. 2018, 360, 4225. doi: 10.1002/adsc.v360.21
	(d) Tu, M.-S.; Liu, S.-J.; Zhong, C.; Zhang, S.; Zhang, H.; Zheng, Y.-L.; Shi, F. J. Org. Chem. 2020, 85, 5403. doi: 10.1021/acs.joc.0c00119
	(e) Sun, Y.; Wang, Z.; Wu, S.; Zhang, Y.; Shi, F. Green Synth. Catal. 2022, 3, 84.
[9]	For some recent examples of other 2-vinylindoles: (a) Yang, W.; Wang, H.; Pan, Z.; Li, Z.; Deng, W. Chin. Chem. Lett. 2020, 31, 721. doi: 10.1016/j.cclet.2019.09.008
	(b) Ye, C.; Yang, W.-L.; Zhai, Y.; Deng, H.; Luo, X.; Kai, G.; Deng, W.-P. Org. Chem. Front. 2020, 7, 3393. doi: 10.1039/D0QO00742K
	(c) Yang, W.-L.; Li, W.; Yang, Z.-T.; Deng, W.-P. Org. Lett. 2020, 22, 4026. doi: 10.1021/acs.orglett.0c01406
[10]	For some selected examples of 4-vinylindoles: (a) Caruana, L.; Fochi, M.; Franchini, M. C.; Ranieri, S.; Mazzanti, A.; Bernardi, L. Chem.-Eur. J. 2015, 21, 17578. doi: 10.1002/chem.201502655 pmid: 26486074
	(b) Romanini, S.; Galletti, E.; Caruana, L.; Mazzanti, A.; Himo, F.; Santoro, S.; Fochi, M.; Bernardi, L. Chem.-Eur. J. 2015, 21, 17578. doi: 10.1002/chem.201502655 pmid: 26486074
	(c) Caruanal, L.; Fochi, M.; Bernardi, L. Synlett 2017, 28, 1530. doi: 10.1055/s-0036-1589494 pmid: 26486074
[11]	For some selected examples of 7-vinylindoles: (a) Shi, F.; Zhang, H.-H.; Sun, X.-X.; Liang, J.; Fan, T.; Tu, S.-J. Chem.-Eur. J. 2015, 21, 3465. doi: 10.1002/chem.v21.8 pmid: 30371094
	(b) Mukherjee, S.; Shee, S.; Poisson, T.; Besset, T.; Biju, A. T. Org. Lett. 2018, 20, 6998. doi: 10.1021/acs.orglett.8b02820 pmid: 30371094
[12]	For some recent examples: (a) Li, T.-Z.; Liu, S.-J.; Sun, Y.-W.; Deng, S.; Tan, W.; Jiao, Y.; Zhang, Y.-C.; Shi, F. Angew. Chem., Int. Ed. 2021, 60, 2355. doi: 10.1002/anie.v60.5
	(b) Chen, K.-W.; Chen, Z.-H.; Yang, S.; Wu, S.-F.; Zhang, Y.-C.; Shi, F. Angew. Chem., Int. Ed. 2022, 61, e202116829.
	(c) Liu, S.-J.; Chen, Z.-H.; Chen, J.-Y.; Ni, S.-F.; Zhang, Y.-C.; Shi, F. Angew. Chem., Int. Ed. 2022, 61, e202112226.
	(d) Sheng, F.-T.; Yang, S.; Wu, S.-F.; Zhang, Y.-C.; Shi, F. Chin. J. Chem. 2022, 40, 2151. doi: 10.1002/cjoc.v40.18
[13]	[4+1] Cyclizations of saccharine-derived aza-dienes: Ling, Z.; Xie, F.; Gridnev, I. D.; Terada, M.; Zhang, W. Chem. Commun. 2018, 54, 9446. doi: 10.1039/C8CC05307C
[14]	For some selected examples of [4+2] cyclizations of saccharine- derived aza-dienes: (a) Gu, J.; Ma, C.; Li, Q.-Z.; Du, W.; Chen, Y.-C. Org. Lett. 2014, 16, 3986. doi: 10.1021/ol501814p
	(b) Li, C.; Jiang, K.; Chen, Y.-C. Molecules 2015, 20, 13642. doi: 10.3390/molecules200813642
	(c) An, Q.; Shen, J.; Butt, N.; Liu, D.; Liu, Y.; Zhang, W. Adv. Synth. Catal. 2015, 357, 3627. doi: 10.1002/adsc.201500550
	(d) Izquierdo, J.; Pericàs, M. A. ACS Catal. 2016, 6, 348. doi: 10.1021/acscatal.5b02121
	(e) Liang, Z.-Q.; Wang, D.-L.; Zhang, C.-L.; Ye, S. Org. Biomol. Chem. 2016, 14, 6422. doi: 10.1039/C6OB01040G
	(f) Stark, D. G.; Young, C. M.; O’Riordan, T. J. C.; Slawina, A. M. Z.; Smith, A. D. Org. Biomol. Chem. 2016, 14, 8068. doi: 10.1039/C6OB01473A
	(g) Wang, L.; Zhu, G.; Tang, W.; Lu, T.; Du, D. Tetrahedron 2016, 72, 6510. doi: 10.1016/j.tet.2016.08.062
[15]	For some recent examples of [4+2] cyclizations of saccharine- derived aza-dienes: (a) Chaithanya Kiran, I. N.; Reddy, R. S.; Lagishetti, C.; Xu, H.; Wang, Z.; He, Y. J. Org. Chem. 2017, 82, 1823. doi: 10.1021/acs.joc.6b02667 pmid: 28019058
	(b) Zhou, Z.; Wang, Z.-X.; Ouyang, Q.; Xiao, W.; Du, W.; Chen, Y.-C. Chem.-Eur. J. 2017, 23, 2945. doi: 10.1002/chem.201605606 pmid: 28019058
	(c) Wang, Z.; Xu, H.; Su, Q.; Hu, P.; Shao, P.-L.; He, Y.; Lu, Y. Org. Lett. 2017, 19, 3111. doi: 10.1021/acs.orglett.7b01221 pmid: 28019058
	(d) Jin, H.; Lia, E.; Huang, Y. Org. Chem. Front. 2017, 4, 2216. doi: 10.1039/C7QO00596B pmid: 28019058
	(e) Ren, X.-R.; Lin, J.-B.; Hua, X.-Q.; Xu, P.-F. Org. Chem. Front. 2019, 6, 2280. doi: 10.1039/C9QO00357F pmid: 28019058
	(f) Zhang, S.; Bacheley, L.; Young, C. M.; Stark, D. G.; O'Riordan, T.; Slawin, A. M. Z.; Smith, A. D. Asian J. Org. Chem. 2020, 9, 1562. doi: 10.1002/ajoc.v9.10 pmid: 28019058
	(g) Song, Y.; Wang, J.; Deng, S.; Liu, G.; Cheng, T. Mol. Catal. 2022, 520, 112165. pmid: 28019058

Entry	LA	Solvent	dr^b	Yield^c/%
1	Cu(OTf)₂	CH₃CN	>95:5	39
2	Mg(OTf)₂	CH₃CN	—	N.R.
3	Fe(OTf)₃	CH₃CN	>95:5	57
4	ZnCl₂	CH₃CN	—	Trace
5	Y(OTf)₃	CH₃CN	—	Trace
6	Sc(OTf)₃	CH₃CN	>95:5	76
7	Yb(OTf)₃	CH₃CN	—	Trace
8	Zn(OTf)₂	CH₃CN	—	N.R.
9	Sc(OTf)₃	DCE	83:17	53
10	Sc(OTf)₃	THF	—	Trace
11	Sc(OTf)₃	Acetone	—	Trace
12	Sc(OTf)₃	AcOEt	>95:5	56
13	Sc(OTf)₃	toluene	75:25	21

Entry	LA	Solvent	dr^b	Yield^c/%
1	Cu(OTf)₂	CH₃CN	>95:5	39
2	Mg(OTf)₂	CH₃CN	—	N.R.
3	Fe(OTf)₃	CH₃CN	>95:5	57
4	ZnCl₂	CH₃CN	—	Trace
5	Y(OTf)₃	CH₃CN	—	Trace
6	Sc(OTf)₃	CH₃CN	>95:5	76
7	Yb(OTf)₃	CH₃CN	—	Trace
8	Zn(OTf)₂	CH₃CN	—	N.R.
9	Sc(OTf)₃	DCE	83:17	53
10	Sc(OTf)₃	THF	—	Trace
11	Sc(OTf)₃	Acetone	—	Trace
12	Sc(OTf)₃	AcOEt	>95:5	56
13	Sc(OTf)₃	toluene	75:25	21

Entry	R/R¹/R² (1)	3	dr^b	Yield^c/%
1	Me/H/Ph (1a)	3aa	>95:5	76
2	Et/H/Ph (1b)	3ba	>95:5	64
3	Bn/H/Ph (1c)	3ca	78:22	62
4	Ph/H/Ph (1d)	3da	85:15	68
5	Me/5-Cl/Ph (1e)	3ea	>95:5	86
6	Me/5-Me/Ph (1f)	3fa	88:12	91
7	Me/6-Cl/Ph (1g)	3ga	>95:5	87
8	Me/H/o-BrC₆H₄ (1h)	3ha	83:17	62
9	Me/H/o-FC₆H₄ (1i)	3ia	91:9	61
10	Me/H/m-MeOC₆H₄ (1j)	3ja	89:11	89
11	Me/H/m-MeC₆H₄ (1k)	3ka	90:10	78
12	Me/H/m-FC₆H₄ (1l)	3la	93:7	65
13	Me/H/m-BrC₆H₄ (1m)	3ma	92:8	70
14	Me/H/p-MeC₆H₄ (1n)	3na	78:22	75

Entry	R/R¹/R² (1)	3	dr^b	Yield^c/%
1	Me/H/Ph (1a)	3aa	>95:5	76
2	Et/H/Ph (1b)	3ba	>95:5	64
3	Bn/H/Ph (1c)	3ca	78:22	62
4	Ph/H/Ph (1d)	3da	85:15	68
5	Me/5-Cl/Ph (1e)	3ea	>95:5	86
6	Me/5-Me/Ph (1f)	3fa	88:12	91
7	Me/6-Cl/Ph (1g)	3ga	>95:5	87
8	Me/H/o-BrC₆H₄ (1h)	3ha	83:17	62
9	Me/H/o-FC₆H₄ (1i)	3ia	91:9	61
10	Me/H/m-MeOC₆H₄ (1j)	3ja	89:11	89
11	Me/H/m-MeC₆H₄ (1k)	3ka	90:10	78
12	Me/H/m-FC₆H₄ (1l)	3la	93:7	65
13	Me/H/m-BrC₆H₄ (1m)	3ma	92:8	70
14	Me/H/p-MeC₆H₄ (1n)	3na	78:22	75

Entry	Ar (2)	3	dr^b	Yield^c/%
1	C₆H₅(2a)	3aa	>95:5	76
2	o-MeOC₆H₄(2b)	3ab	93:7	75
3	o-ClC₆H₄(2c)	3ac	>95:5	62
4	m-MeOC₆H₄ (2d)	3ad	91:9	76
5	m-MeC₆H₄ (2e)	3ae	>95:5	62
6	p-MeOC₆H₄ (2f)	3af	88:12	71
7	p-FC₆H₄ (2g)	3ag	>95:5	89
8	p-ClC₆H₄ (2h)	3ah	>95:5	95
9	2-Naphthyl (2i)	3ai	>95:5	71
10	3-Thienyl (2j)	3aj	87:13	80
11	5-Methyl-2-furyl (2k)	3ak	>95:5	56

Lewis酸催化下3-烷基-2-吲哚烯与α,β-不饱和N-磺酰基亚胺的[2+4]环化反应

Lewis Acid-Catalyzed [2+4] Cyclization of 3-Alkyl-2-vinylindoles with α,β-Unsaturated N-Sulfonyl Ketimines

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[3]	Chen Jinyang, Hu Li, Wang Haiying, Tan Honghui. Iodine-Catalyzed Telluration of Indole Derivatives with Diarylditellurides for Synthesis of 3-Aryltellurylindoles [J]. Chin. J. Org. Chem., 2019, 39(7): 2048-2052.
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[12]	Gao Wentao, Lan Shuai, Zheng Hongmei, Bairenqing Zhuoma. A Facile Synthesis of Thiazole Skeleton-Containing Indole Derivatives [J]. Chin. J. Org. Chem., 2015, 35(1): 144-151.
[13]	Yu Haifeng, Liao Peiqiu, Diao Quanping, Li Tiechun, Xin Guang, Han Linan, Hou Dongyan. Selective Synthesis of 3-(3-Indolyl)-3-(methylthio)acrylate and 3-(3-Indolyl)-3-oxopropanoate [J]. Chin. J. Org. Chem., 2014, 34(9): 1851-1856.
[14]	Feng Yadong, Zhang Hong, Cheng Guolin, Cui Xiuling. Synthesis of Indole Derivatives via Domino Reactions [J]. Chin. J. Org. Chem., 2014, 34(8): 1499-1508.
[15]	Yu Haifeng, Li Tiechun, Liao Peiqiu, Diao Quanping, Xin Guang, Hou Dongyan. Acidity-Controlled Indolylation of 3, 3-Bis(ethylthio)acrylate [J]. Chin. J. Org. Chem., 2014, 34(5): 956-961.

Entry	T/℃	n(1a):n(2a)	x	dr^b	Yield^c/%
1	70	1:2	1	>95:5	76
2	50	1:2	1	>95:5	22
3	90	1:2	1	>95:5	53
4	70	1:1.5	1	>95:5	22
5	70	1:3	1	>95:5	72
6	70	1.5:1	1	>95:5	55
7	70	2:1	1	>95:5	68
8	70	3:1	1	>95:5	62
9	70	1:2	0.5	>95:5	71
10	70	1:2	2	>95:5	70
11^d	70	1:2	1	>95:5	68

Entry	T/℃	n(1a):n(2a)	x	dr^b	Yield^c/%
1	70	1:2	1	>95:5	76
2	50	1:2	1	>95:5	22
3	90	1:2	1	>95:5	53
4	70	1:1.5	1	>95:5	22
5	70	1:3	1	>95:5	72
6	70	1.5:1	1	>95:5	55
7	70	2:1	1	>95:5	68
8	70	3:1	1	>95:5	62
9	70	1:2	0.5	>95:5	71
10	70	1:2	2	>95:5	70
11^d	70	1:2	1	>95:5	68