- Pilot in Vivo Structure-Activity Relationship of Dihydromethysticin in Blocking 4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone-Induced O6-Methylguanine and Lung Tumor in A/J Mice
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(+)-Dihydromethysticin was recently identified as a promising lung cancer chemopreventive agent, while (+)-dihydrokavain was completely ineffective. A pilot in vivo structure-activity relationship (SAR) was explored, evaluating the efficacy of its analogs in blocking 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone-induced short-term O6-methylguanine and long-term adenoma formation in the lung tissues in A/J mice. Both results revealed cohesive SARs, demonstrating that the methylenedioxy functional group in DHM is essential while the lactone functional group tolerates modifications.
- Puppala, Manohar,Narayanapillai, Sreekanth C.,Leitzman, Pablo,Sun, Haifeng,Upadhyaya, Pramod,O'Sullivan, M. Gerard,Hecht, Stephen S.,Xing, Chengguo
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supporting information
p. 7935 - 7940
(2017/10/06)
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- Lewis base-catalyzed divergent isomerizations of 5-hydroxyl-2,3-dienoate
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A divergent isomerization of 5-hydroxyl-2,3-dienoate 1 catalyzed by Lewis base has been developed, the phosphine catalyst leads to 5-oxohex-2(3)-enoates 2 while DABCO catalyst affords 3-ethoxy α,β-unsaturated lactone 3.
- Dong, Wei,Hu, Pengfei,Hu, Jian,Tong, Xiaofeng
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p. 1682 - 1685
(2014/03/21)
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- Synthesis of β-methoxyacrylate natural products based on box-Pd IIcatalyzed intermolecular methoxycarbonylation of alkynoles
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Bis(oxazoline)-palladium(II) catalyzed carbonylation of homopropargyl alcohols afforded acyclic methoxyacrylate 2 and 6-membered lactone 3a-k in good combined yield. In the case of propargyl alcohols, 5-membered lactones 3p, 3q, 16 were obtained in moderate yields. The one-pot synthesis of kawa lactones 3a, 3r, 3s and formal synthesis of dihydroxycystothiazole A and dihydroxycystothiazole C are presented. To elucidate the stereochemistry of (+)-annularin G and (-)-annularin H, the first asymmetric syntheses of these natural products were achieved.
- Motodate, Satoshi,Kobayashi, Takuya,Fujii, Mikio,Mochida, Tomoyuki,Kusakabe, Taichi,Katoh, Shigeki,Akita, Hiroyuki,Kato, Keisuke
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experimental part
p. 2221 - 2230
(2011/06/21)
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- Efficient enantioselective hetero-diels-alder reaction of brassard's diene with aliphatic aldehydes: A one-step synthesis of (R)-(+)-kavain and (S)-(+)-dihydrokavain
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An efficient catalytic asymmetric hetero-Diels-Alder reaction of Brassard's diene with aliphatic aldehydes was reported The catalyst which was generated from (R)-BINOL, Ti(i-PrO)4, and 4-picolyl chloride hydrochloride, promoted the reaction smoothly to afford the corresponding α, β-unsaturated λ-lactone derivatives in moderate-to-good yields (46-79%) with high enantioselectivities (up to 88% ee) Natural products (R)-(+)-kavain (70% ee, > 99% ee after single re crystallization) and (S)-(+)-dihydrokavain (84% ee) were also prepared in one step by using this methodology.
- Lin, Lili,Chen, Zhenling,Yang, Xu,Liu, Xiaohua,Feng, Xiaoming
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supporting information; scheme or table
p. 1311 - 1314
(2009/04/06)
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- Versatile asymmetric synthesis of the kavalactones: First synthesis of (+)-kavain
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(Equation Presented) Three asymmetric pathways to the kavalactones have been developed. The first method is chiral auxiliary-based and utilizes aldol reactions of N-acetyl thiazolidinethiones followed by a malonate displacement/decarboxylation reaction. The second approach uses the asymmetric catalytic Mukaiyama additions of dienolate nucleophile equivalents developed by Carreira and Sato. Finally, tin-substituted intermediates, prepared by either of these routes, can serve as advanced general precursors of kavalactone derivatives via Pd(0)-catalyzed Stille couplings with aryl halides.
- Smith, Thomas E.,Djang, Mabel,Velander, Alan J.,Downey, C. Wade,Carroll, Kathleen A.,Van Alphen, Sophie
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p. 2317 - 2320
(2007/10/03)
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- Polymer-supported electron-rich diene for hetero Diels-Alder reactions
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A Brassard diene analogue was grafted on a modified Merrifield resin and used in a hetero Diels-Alder reaction with various aldehydes or ketones. The reaction gave access to 6-substituted 5,6-dihydropyrones (5a-u). This new immobilized electron-rich diene is more stable than the corresponding native diene, and is a versatile supported reagent.
- Pierres, Camille,George, Pascal,Van Hijfte, Luc,Ducep, Jean-Bernard,Hibert, Marcel,Mann, André
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p. 3645 - 3647
(2007/10/03)
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- Wood preservative
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A wood preservative that comprises as an active ingredient a Piper methysticum, plant or a processed product thereof or a compound represented by Formula (I): wherein R1, R2, R3, R4 and R16 are same or different and each denotes a hydrogen atom, hydroxy or a C1-4 alkoxy, or R1 and R2 are taken together to form a group represented by —O—(CH2)n—O— wherein n is an integer of 1 to 3, R5 is a C1-4 alkoxy and X is —CH=CH—, —CH2—CH2— or epoxyethylene, and the bond: denotes a single bond or a double bond can prevent the attacking wood by an insect harmful to the wood and also prevents the appearance and the growth of a wood-rotting fungus or a wood- staining fungus while being highly safe to humans and animals without exerting no adverse effect on the environment.
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