Advances on the α- and β-Reactions of Deconjugated Butenolides

doi:10.6023/cjoc202210035

Abstract

Developing the construction methods of γ-lactone derivatives due to their anti-inflammatory, antitumor, anti-cancer and other biological activities has important value in organic synthesis. Among them, the deconjugated butenolides have shown great potential and advantages in the synthesis of γ-lactone derivatives. As the direct and efficient method, it has attracted more attentions of chemists, and is one of the hot topics of organic synthesis in recent years. The α- and β-reactions of deconjugated butenolides are reviewed, in which the characteristics of various reaction systems and the mechanisms of some reactions are discussed. At the same time, the future development is prospected in this field.

Key words: deconjugated butenolides, α-addition, β-addition, nucleophilic attack

Cite this article

Lin Zhou, Hong Yang, Chuan Yang, Zhigang Zhao, Qinghan Li. Advances on the α- and β-Reactions of Deconjugated Butenolides[J]. Chinese Journal of Organic Chemistry, 2023, 43(7): 2407-2424.

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Fig. & Tab. 23

Figure 1. Pharmacologically active molecules containing γ- lactone

Figure 2. Reactivity comparison between 2-silyloxy furans, conjugated butenolides and deconjugated butenolides

Scheme 1. Commonly encountered reactivities of deconjugated butenolides

Scheme 2. Synthetic methods of deconjugated butenolides

Scheme 3. Aldol condensation of deconjugated butenolides with alkyl aldehydes

Scheme 4. Michael addition of deconjugated butenolides with chalcones

Scheme 5. Diastereoselective α-Aldol condensation of α-angelica lactone with β-halo-α-ketoesters

Scheme 6. Asymmetric α,γ-double Michael additions of α-angelica lactone with nitroolefines

Scheme 7. α-Addition cascade elimination of deconjugated butenolides with cyclic N-sulfonylated imines

Scheme 8. Direct α-addition cascade isomerization of deconjugated butenolides with α-ketoesters

Scheme 9. Direct α-addition cascade isomerization of α-ange- lica lactone with trifluoromethylacetophenone

Scheme 10. Direct α-addition cascade transesterification of deconjugated butenolides with o-QMs

Scheme 11. Direct α-addition cascade aminolysis of deconjugated butenolides with cyclic vinyl carbamates

Scheme 12. α-Substitution cascade aminolysis of deconjugated butenolides with cyclic propargylic carbamates

Scheme 13. Direct α-bis-sulfenylation of deconjugated butenolides

Scheme 14. Direct α-sulfenylation of α-methyl-γ-phenyl deconjugated butenolides

Scheme 15. Catalytic asymmetric α-sulfenylation of α-methyl- γ-phenyl deconjugated butenolides

Scheme 16. Direct β-1,6-conjugate addition of deconjugated butenolides with p-quinone methides

Scheme 17. β-Aldol condensation cascade transesterification of deconjugated butenolides with alkyl aldehydes

Scheme 18. Direct β-addition cascade intramolecular ammonolysis cyclization of α-angelicalactone

Scheme 19. Aerobic oxidative cross-coupling cascade aminolysis of α-angelicalactone with glycine esters

Scheme 20. Proposed mechanism of the β-addition cascade ammonolysis cyclization of α-angelicalactone

Scheme 21. β,γ-Bifunctional reaction of deconjugated butenolides with nitrosocarbonyl compounds

References 41

[1]	For selected reviews and examples, see: (a) Kitson, R.R.A.; Millemaggi, A.; Taylor, R., J. K. Angew. Chem., Int. Ed. 2009, 48, 9426. pmid: 16468720
	(b) Lone, S. H.; Bhat, K. A.; Khuroo, M. A. Chem.-Biol. Interact. 2015, 240, 180. doi: 10.1016/j.cbi.2015.08.015 pmid: 16468720
	(c) Yu, X.; Che, Z.; Xu, H. Chem.-Eur. J. 2017, 23, 4467. doi: 10.1002/chem.201602472 pmid: 16468720
	(d) Curti, C.; Battistini, L.; Sartori, A.; Zanardi, F. Chem. Rev. 2020, 120, 2448. doi: 10.1021/acs.chemrev.9b00481 pmid: 16468720
	(e) Choudhury, A. R.; Mukherjee, S. Chem. Soc. Rev. 2020, 49, 6755. doi: 10.1039/c9cs00346k pmid: 16468720
	(f) Boeckman, R. K.; Pero, J. E.; Boehmler, D. J. J. Am. Chem. Soc. 2006, 128, 11032. pmid: 16468720
	(g) Robichaud, J.; Tremblay, F. Org. Lett. 2006, 8, 597. pmid: 16468720
	(h) Zhang, X.; Yin, Y.; Zhou, Y.; Zhu, T.; Wang, M.; Gao, H. Chin. J. Chem. 2022, 40, 617. doi: 10.1002/cjoc.v40.5 pmid: 16468720
	(i) You, J.-Q.; Liu, Y.-N.; Zhou, J.-S.; Sun, X.-Y.; Lei, C.; Mu, Q.; Li, J.-Y.; Hou, A.-J. Chin. J. Chem. 2022, 40, 2882. doi: 10.1002/cjoc.v40.24 pmid: 16468720
	(j) Zhang, H.; Nan, F. Chin. J. Chem. 2013, 31, 84. doi: 10.1002/cjoc.201200695 pmid: 16468720
	(k) Tang, B.; Guan, A.; Zhao, Y.; Jiang, J.; Wang, M.; Zhou, L. Chin. J. Chem. 2017, 35, 1133. doi: 10.1002/cjoc.v35.7 pmid: 16468720
	(l) Wang, Y.; Chen, B.; He, X.; Gui, J. Chin. J. Chem. 2020, 38, 1339. doi: 10.1002/cjoc.v38.11 pmid: 16468720
[2]	(a) Ma, S.-M.; Shi, Z.-J. Chin. J. Chem. 2001, 19, 1280. doi: 10.1002/cjoc.20010191220
	(b) Wang, J. P.; Chang, X. H.; Tian, X. Z.; Chen, Q. H. Acta Chim. Sinica 2003, 61, 411 (in Chinese).
	(王建平, 常新红, 田欣哲, 陈庆华, 化学学报, 2003, 61, 411.)
	(c) Zhao, Y.; Jiang, S.; Guo, Y.-W.; Yao, Z.-J. Chin. J. Chem. 2005, 23, 173. doi: 10.1002/(ISSN)1614-7065
	(d) Zhao, Y.; Tang, B.; Liu, X.; Li, W. Z.; Huang, M. Y.; Wang, M. A. Chin. J. Org. Chem. 2017, 37, 975 (in Chinese). doi: 10.6023/cjoc201611013
	(赵宇, 汤博, 刘鑫磊, 李婉祯, 黄铭一, 王明安, 有机化学, 2017, 37, 975.) doi: 10.6023/cjoc201611013
	(e) Li, X.; Zhu, K.; Han, Q.; Lu, X. X.; Li, M. J.; Ling, Y.; Duan, H. X. Chin. J. Org. Chem. 2022, 42, 202 (in Chinese).
	(李想, 朱凯, 韩清, 路星星, 李明君, 凌云, 段红霞, 有机化学, 2022, 42, 202.)
	(f) Zhang, Q.; Li, Y. H.; Xu, L. C.; Ma, H. Y.; Li, X. D.; Wang, M. A. Chin. J. Org. Chem. 2022, 42, 2438 (in Chinese). doi: 10.6023/cjoc202203033
	(张倩, 李益豪, 许磊川, 马好运, 李向东, 王明安, 有机化学, 2022, 42, 2438.) doi: 10.6023/cjoc202203033
[3]	(a) Das, U.; Chen, Y.-R.; Tsai, Y.-L.; Lin, W. Chem.-Eur. J. 2013, 19, 7713. doi: 10.1002/chem.v19.24
	(b) Rout, S.; Das, A.; Singh, V. K. Chem. Commun. 2017, 53, 5143. doi: 10.1039/C7CC01763D
[4]	(a) Adekenov, S. M.; Mukhametzhanov, M. N.; Kagarlitskii, A. D.; Kupriyanov, A. N. Khim. Prir. Soedin. 1982, 655.
	(b) Zhangabylov, N. S.; Dederer, L. Y.; Gorbacheva, L. B.; Vasilêva, S. V.; Terekhov, A. S.; Adekenov, S. M. Pharm. Chem. J. 2004, 38, 651. doi: 10.1007/s11094-005-0052-9
[5]	Aubert, S.; Katsina, T.; Arseniyadis, S. Org. Lett. 2019, 21, 2231. doi: 10.1021/acs.orglett.9b00521
[6]	For selected reviews, see: (a) Jusseau, X.; Chabaud, L.; Guillou, C. Tetrahedron 2014, 70, 2595. doi: 10.1016/j.tet.2014.01.057
	(b) Roselló, M. S.; del Pozoa, C.; Fustero, S. Synthesis 2016, 48, 2553. doi: 10.1055/s-0035-1561650
	(c) Mao, B.; Fañanas-Mastral, M.; Feringa, B. L. Chem. Rev. 2017, 117, 10502. doi: 10.1021/acs.chemrev.7b00151
	(d) Yin, Y.; Jiang, Z. ChemCatChem 2017, 9, 4306. doi: 10.1002/cctc.v9.23
	(e) Li, H.; Yin, L. Tetrahedron Lett. 2018, 59, 4121. doi: 10.1016/j.tetlet.2018.10.012
[7]	For selected examples on activated silyloxyfurans, see: (a) Redero, E.; Sandoval, C.; Bermejo, F. Tetrahedron 2001, 57, 9597. pmid: 20583835
	(b) Singh, R. P.; Foxman, B. M.; Deng, L. J. Am. Chem. Soc. 2010, 132, 9558. doi: 10.1021/ja103331t pmid: 20583835
	(c) Meshram, H. M.; Ramesh, P.; Reddy, B. C.; Sridhar, B.; Yadav, J. S. Tetrahedron 2011, 67, 3150. doi: 10.1016/j.tet.2011.02.033 pmid: 20583835
	(d) Mao, B.; Ji, Y.; Fananas-Mastral, M.; Caroli, G.; Meetsma, A.; Feringa, B. L. Angew. Chem., Int. Ed. 2012, 51, 3168. doi: 10.1002/anie.v51.13 pmid: 20583835
	(e) Chen, W.; Hartwig, J. F. J. Am. Chem. Soc. 2012, 134, 15249. doi: 10.1021/ja306850b pmid: 20583835
	(f) Woyciechowska, M.; Forcher, G.; Buda, S.; Mlynarski, J. Chem. Commun. 2012, 48, 11029. doi: 10.1039/c2cc36656h pmid: 20583835
	(g) Kong, S.; Fan, W.; Lyu, H.; Zhan, J.; Miao, X.; Miao, Z. Synth. Commun. 2014, 44, 936. doi: 10.1080/00397911.2013.837926 pmid: 20583835
	(h) Wang, Y.; Xing, F.; Xue, M.; Du, G.-F.; Guo, X.-H.; Huang, K.-W.; Dai, B. Synthesis 2016, 48, 79. doi: 10.1055/s-00000084 pmid: 20583835
	(i) Adamkiewicz, A.; Węglarz, I.; Butkiewicz, A.; Woyciechowska, M.; Mlynarski, J. Adv. Synth. Catal. 2020, 362, 667. doi: 10.1002/adsc.v362.3 pmid: 20583835
[8]	(a) Zhang, Y.; Yu, C.; Ji, Y.; Wang, W. Chem.-Asian J. 2010, 5, 1303.
	(b) Huang, H.; Yu, F.; Jin, Z.; Li, W.; Wu, W.; Liang, X.; Ye, J. Chem. Commun. 2010, 46, 5957. doi: 10.1039/c0cc01054e
	(c) Luo, J.; Wang, H.; Han, X.; Xu, L.-W.; Kwiatkowski, J.; Huang, K.-W.; Lu, Y. Angew. Chem., Int. Ed. 2011, 50, 1861. doi: 10.1002/anie.v50.8
	(d) Yin, L.; Takada, H.; Lin, S.; Kumagai, N.; Shibasaki, M. Angew. Chem., Int. Ed. 2014, 53, 5327. doi: 10.1002/anie.v53.21
[9]	(a) Cui, H. L.; Huang, J. R.; Lei, J.; Wang, Z. F.; Chen, S.; Wu, L.; Chen, Y. C. Org. Lett. 2010, 12, 720. doi: 10.1021/ol100014m
	(b) Wu, Y.; Singh, R. P.; Deng, L. J. Am. Chem. Soc. 2011, 133, 12458. doi: 10.1021/ja205674x
	(c) Griswold, J. A.; Johnson, J. S. ACS Catal. 2019, 9, 11614. doi: 10.1021/acscatal.9b04405
	(d) Yu, C.; Ji, P.; Zhang, Y.; Meng, X.; Wang, W. Org. Lett. 2021, 23, 7656. doi: 10.1021/acs.orglett.1c02916
	(e) Dai, Z.-Y.; Wang, P.-S.; Gong, L.-Z. Chem. Commun. 2021, 57, 6748. doi: 10.1039/D1CC02295D
[10]	(a) Helberger, V. J. H.; Ulubey, S.; Civelekoglu, H. Justus Liebigs Ann. Chem. 1949, 561, 215. doi: 10.1002/(ISSN)1099-0690
	(b) Karwa, S.; Gajiwala, V. M.; Heltzel, J.; Patil, S. K. R.; Lund, C. R. F. Catal. Today 2016, 263, 16. doi: 10.1016/j.cattod.2015.06.020
[11]	Pelter, A.; Rowlands, M. Tetrahedron Lett. 1987, 28, 1203.
[12]	Marshall, J. A.; Wolf, M. A.; Wallace, E. M. J. Org. Chem. 1997, 62, 367. pmid: 11671411
[13]	(a) Osman, N. A.; Mahmoud, A. H.; Allara, M.; Niess, R.; Abouzid, K. A.; Marzo, V. D.; Abadi, A. H. Bioorg. Med. Chem. 2010, 18, 8463. doi: 10.1016/j.bmc.2010.10.050 pmid: 19606900
	(b) Muratore, M. E.; Holloway, C. A.; Pilling, A. W.; Storer, R. I.; Trevitt, G.; Dixon, D. J. J. Am. Chem. Soc. 2009, 131, 10796. doi: 10.1021/ja9024885 pmid: 19606900
[14]	Lima, C. G. S.; Monteiro, J. L.; Lima, T. Paixão, M. W.; Corrêa, A. G. ChemSusChem. 2018, 11, 25. doi: 10.1002/cssc.v11.1
[15]	For selected recent reports on the γ-addition of deconjugated butenolides, see: (a) Quintard, A.; Lefranc, A.; Alexakis, A. Org. Lett. 2011, 13, 1540. doi: 10.1021/ol200235j pmid: 22952199
	(b) Zhou, L.; Lin, L.-L.; Ji, J.; Xie, M.-S.; Liu, X.-H.; Feng, X.-M. Org. Lett. 2011, 13, 3056. doi: 10.1021/ol200939t pmid: 22952199
	(c) Zhang, W.; Tan, D.; Lee, R.; Tong, G.; Chen, W.; Qi, B.; Huang, K.-W.; Tan, C.-H.; Jiang, Z. Angew. Chem., Int. Ed. 2012, 51, 10069. doi: 10.1002/anie.201205872 pmid: 22952199
	(d) Manna, M. S.; Kumar, V.; Mukherjee, S. Chem. Commun. 2012, 48, 5193. doi: 10.1039/C2CC31700A pmid: 22952199
	(e) Manna, M. S.; Mukherjee, S. Chem.-Eur. J. 2012, 18, 15277. doi: 10.1002/chem.v18.48 pmid: 22952199
	(f) Ji, J.; Lin, L.-L.; Zhou, L.; Zhang, Y.-H.; Liu, Y.-B.; Liu, X.-H.; Feng X.-M. Adv. Synth. Catal. 2013, 355, 2764. pmid: 22952199
	(g) Yang, D.; Wang, L.; Zhao, D.; Han, F.; Zhang, B.; Wang, R. Chem.-Eur. J. 2013, 19, 4691. doi: 10.1002/chem.201204466 pmid: 22952199
[16]	For selected reports on the γ-addition of deconjugated butenolides, see: (a) Guo, Y.-L.; Jia, L.-N.; Peng, L.; Qi, L.-W.; Zhou, J.; Tian, F.; Xu, X.-Y.; Wang, L. -X. RSC Adv. 2013, 3, 16973. doi: 10.1039/c3ra43344g
	(b) Kumar, V.; Ray, B.; Rathi, P.; Mukherjee, S. Synthesis 2013, 45, 1641. doi: 10.1055/s-00000084
	(c) Manna, M. S.; Mukherjee, S. Chem. Sci. 2014, 5, 1627. doi: 10.1039/C3SC53102C
	(d) Li, X.; Lu, M.; Dong, Y.; Wu, W.; Qian, Q.; Ye, J.; Dixon, D. J. Nat. Commun. 2014, 4, 4479.
	(e) Wang, Z.-H.; Wu, Z.-J.; Huang, X.-Q.; Yue, D.-F.; You, Y.; Xu, X.-Y.; Zhang, X.-M.; Yuan, W.-C. Chem. Commun. 2015, 51, 15835. doi: 10.1039/C5CC06383C
	(f) Guo, H.; Xing, F.; Du, G.-F.; Huang, K.-W.; Dai, B.; He, L. J. Org. Chem. 2015, 80, 12606. doi: 10.1021/acs.joc.5b01845
[17]	For selected reports on the γ-addition of deconjugated butenolides, see: (a) Sekikawa, T.; Kitaguchi, T.; Kitaura, H.; Minami, T.; Hatanaka, Y. Org. Lett. 2015, 17, 3026. doi: 10.1021/acs.orglett.5b01224 pmid: 26646367
	(b) Lagoutte, R.; Besnard, C.; Alexakis, A. Eur. J. Org. Chem. 2016, 4372. pmid: 26646367
	(c) Simlandy, A. K.; Mukherjee, S. Org. Biomol. Chem. 2016, 14, 5659. doi: 10.1039/c5ob02362a pmid: 26646367
	(d) Tang, Q.; Lin, L.-L.; Ji, J.; Hu, H.-P.; Liu, X.-H.; Feng, X.-M. Chem.-Eur. J. 2017, 23, 16447. doi: 10.1002/chem.v23.65 pmid: 26646367
	(e) Ji, J.; Lin, L.-L.; Tang, Q.; Kang, T.-F.; Liu, X.-H.; Feng, X.-M. ACS Catal. 2017, 7, 3763. doi: 10.1021/acscatal.7b00590 pmid: 26646367
	(f) Trost, B. M.; Gnanamani, E.; Tracy, J. S.; Kalnmals, C. J. Am. Chem. Soc. 2017, 139, 18198. doi: 10.1021/jacs.7b11361 pmid: 26646367
	(g) Rout, S.; Joshi, H.; Singh, V. K. Org. Lett. 2018, 20, 2199. doi: 10.1021/acs.orglett.8b00493 pmid: 26646367
[18]	For selected reports on the γ-addition of deconjugated butenolides, see: (a) Sakai, T.; Hirashima, S.; Matsushima, Y.; Nakano, T.; Ishii, D.; Yamashita, Y.; Nakashima, K.; Koseki, Y.; Miura, T. Org. Lett. 2019, 21, 2606. doi: 10.1021/acs.orglett.9b00574
[19]	Jefford, C. W.; Jaggi, D.; Boukouvalas, J. J. Chem. Soc., Chem. Commun. 1988, 1595.
[20]	Egorova, A. Y.; Timofeeva, Z. Y. Russ. J. Gen. Chem. 2003, 73, 655. doi: 10.1023/A:1025625511411
[21]	Griswold, J. A.; Horwitz, M. A.; Leiva, L. V.; Johnson, J. S. J. Org. Chem. 2017, 82, 2276. doi: 10.1021/acs.joc.6b03059 pmid: 28164699
[22]	(a) Mengel, A.; Reiser, O. Chem. Rev. 1999, 99, 1191. pmid: 11749444
	(b) Evans, D. A.; Siska, S. J.; Cee, V. J. Angew. Chem., Int. Ed. 2003, 42, 1761. doi: 10.1002/anie.200350979 pmid: 11749444
	(c) Cee, V. J.; Cramer, C. J.; Evans, D. A. J. Am. Chem. Soc. 2006, 128, 2920. doi: 10.1021/ja0555670 pmid: 11749444
[23]	Yang, M.; Chen, C.; Yi, X.; Li, Y.; Wu, X.; Li, Q.; Ban, S. Org. Biomol. Chem. 2019, 17, 2883. doi: 10.1039/C9OB00330D
[24]	Li, Feng.; Wang, J.; Pei, W.; Ma, H.; Li, H.; Cui, M.; Peng, S.; Wang, S.; Liu, L. Tetrahedron Lett. 2018, 59, 3010. doi: 10.1016/j.tetlet.2018.06.062
[25]	Trost, B. M.; Joey Hung, C.-I.; Scharf, M. J. Angew. Chem., Int. Ed. 2018, 57, 11408. doi: 10.1002/anie.v57.35
[26]	Huang, Z-Y.; Yang, H.; Zhou, L.; Li, Q.-H.; Zhao, Z.-G. Tetrahedron. 2022, 112, 132740. doi: 10.1016/j.tet.2022.132740
[27]	Wu, Bo.; Yu, Z.; Gao, X.; Lan, Y.; Zhou, Y.-G. Angew. Chem., Int. Ed. 2017, 56, 4006. doi: 10.1002/anie.201700437 pmid: 28247568
[28]	(a) Green, A. G.; Liu, P.; Merlic, C. A.; Houk, K. N. J. Am. Chem. Soc. 2014, 136, 4575. doi: 10.1021/ja411699u
	(b) Wang, T.; Yu, Z.; Hoon, D. L.; Phee, C. Y.; Lan, Y.; Lu, Y. J. Am. Chem. Soc. 2016, 138, 265. doi: 10.1021/jacs.5b10524
[29]	Wang, Y.-N.; Xiong, Q.; Lu, L.-Q.; Zhang, Q.-L.; Wang, Y.; Lan, Y.; Xiao, W.-J. Angew. Chem., Int. Ed. 2019, 58, 11013. doi: 10.1002/anie.v58.32
[30]	Xu, Y.-W.; Hu, X.-P. Org. Lett. 2019, 21, 8091. doi: 10.1021/acs.orglett.9b03081
[31]	Hattori, G.; Sakata, K.; Matsuzawa, H.; Tanabe, Y.; Miyake, Y.; Nishibayashi, Y. J. Am. Chem. Soc. 2010, 132, 10592. doi: 10.1021/ja1047494 pmid: 20617844
[32]	Zhao, J.-Q.; Luo, S.-W.; Zhang, X.-M.; Xu, X.-Y.; Zhou, M.-Q.; Yuan, W.-C. Tetrahedron 2017, 73, 5444. doi: 10.1016/j.tet.2017.07.053
[33]	Sharma, B. M.; Shinde, D. R.; Jain, R.; Begari, E.; Satbhaiya, S.; Gonnade, R. G.; Kumar, P. Org. Lett. 2018, 20, 2787. doi: 10.1021/acs.orglett.8b00745
[34]	Masuyama, Y.; Kobayashi, Y.; Yanagi, R.; Kurusu, Y. Chem. Lett. 1992, 2039.
[35]	Isambert, N.; Cruz, M.; Arévalo, M. J.; Gómez, E.; Lavilla, R. Org. Lett. 2007, 9, 4199. pmid: 17867693
[36]	Huo, C.; Yuan, Yong. J. Org. Chem. 2015, 80, 12704. doi: 10.1021/acs.joc.5b02354
[37]	Huo, C.; Yuan, Y.; Chen, F.; Tang, J.; Wang, Y. Org. Lett. 2015, 17, 4208. doi: 10.1021/acs.orglett.5b01985
[38]	Zhou, H.; Yang, X.; Li, S.; Zhu, Y.; Li, Y.; Zhang, Y. Org. Biomol. Chem. 2018, 16, 6728. doi: 10.1039/C8OB01844H
[39]	(a) For reviews on nitrosocarbonyl chemistry, see: Palmer, L. I.; Frazier, C. P.; Read De Alaniz, J. Synthesis 2014, 46, 269. doi: 10.1055/s-00000084
	(b) Maji, B.; Yamamoto, H. Bull. Chem. Soc. Jpn. 2015, 88, 753. doi: 10.1246/bcsj.20150040
	(c) Memeo, M. G.; Quadrelli, P. Chem. Rev. 2017, 117, 2108. doi: 10.1021/acs.chemrev.6b00684
	(d) Dana, S.; Ramakrishna, I.; Baidya, M. Synthesis 2017, 49, 3281. doi: 10.1055/s-0036-1590793
[40]	Mallik, S.; Bhajammanavar, V.; Baidya, M. Org. Lett. 2020, 22, 1437. doi: 10.1021/acs.orglett.0c00039
[41]	(a) Payette, J. N.; Yamamoto, H. J. Am. Chem. Soc. 2008, 130, 12276. doi: 10.1021/ja804325f pmid: 18722431
	(b) Maji, B.; Yamamoto, H. Angew. Chem., Int. Ed. 2014, 53, 14472. doi: 10.1002/anie.201408893 pmid: 18722431

非共轭丁烯内酯α-和β-位反应研究进展