20213-26-7Relevant academic research and scientific papers
Two expedient syntheses of β-lapachone
Alves, Glaucia B. C.,Lopes, Rosangela S. C.,Lopes, Claudio C.,Snieckus, Victor
, p. 1875 - 1877 (1999)
Two short syntheses of β-llapachone (1) from readily available naphthols 2a,b and 3-methylbut-2-enal via a mild phenylboronic acid-mediated cyclization to 2H-chromenes 3a,b is reported.
Molecular iodine catalyst promoted synthesis of chromans and 4-aryl-3,4-dihydrobenzopyran-2-ones via [3+3] cyclocoupling
Naik, Mayuri M.,Kamat, Durga P.,Tilve, Santosh G.,Kamat, Vijayendra P.
, p. 5221 - 5233 (2014/07/08)
Molecular iodine as an inexpensive catalyst is described in the construction of 2-substituted or 2,2-disubstituted chromans and 4-aryl-3,4-dihydrobenzopyran-2-ones via [3+3] cyclocoupling. For the synthesis of chromans, phenols and allylic alcohols were refluxed in chloroform in presence of 20 mol % I2 while [3+3] cyclocoupling of phenols and cinnamic acids proceeded to give 4-aryl-3,4-dihydrobenzopyran-2-ones using 30 mol % I2. Later reaction occurs via a tandem hydroarylation- esterification process at 120-130°C under solvent free conditions. Chromans were obtained in 20-92% yields and substituted 4-aryl-3,4-dihydrobenzopyran-2- ones were obtained in 5-85% yields.
Molecular iodine catalyst promoted synthesis of chromans and 4-aryl-3,4-dihydrobenzopyran-2-ones via [3+3] cyclocoupling
Naik, Mayuri M.,Kamat, Durga P.,Tilve, Santosh G.,Kamat, Vijayendra P.
, p. 5221 - 5233 (2014/12/10)
Molecular iodine as an inexpensive catalyst is described in the construction of 2-substituted or 2,2-disubstituted chromans and 4-aryl-3,4-dihydrobenzopyran-2-ones via [3+3] cyclocoupling. For the synthesis of chromans, phenols and allylic alcohols were refluxed in chloroform in presence of 20 mol % I2while [3+3] cyclocoupling of phenols and cinnamic acids proceeded to give 4-aryl-3,4-dihydrobenzopyran-2-ones using 30 mol % I2. Later reaction occurs via a tandem hydroarylation-esterification process at 120-130 °C under solvent free conditions. Chromans were obtained in 20-92% yields and substituted 4-aryl-3,4-dihydrobenzopyran-2-ones were obtained in 5-85% yields.
Concise synthesis of (±)-rhinacanthin A, dehydro α-lapachone, and β-lapachone, and pyranonaphthoquinone derivatives
Wang, Xue,Chen, Ye,Lee, Yong Rok
experimental part, p. 153 - 156 (2011/11/01)
A concise synthesis of (±)-rhinacanthin A is achieved in two steps by epoxidation of dehydro-α-lapachone, followed by chemo-and regioselective reduction. Dehydro-α-lapachone was also synthesized in two steps starting from 4-methoxy-1-naphthol by ethylenediamine diaetate (EDDA)-catalyzed benzopyran formation and a CAN-mediated oxidation reaction. β-Lapachone was synthesized in three steps from 4-methoxy-1-naphthol by benzopyran formation, catalytic hydrogenation, and Jones oxidation. As additional reactions, synthesis of pyranonaphthoquinone derivatives with the pyranokunthone B skeleton has been achieved in a single step from readily available 2-hydroxy-6-methoxy-1,4-naphthoquinone and 2-hydroxy-7-methoxy-1,4- naphthoquinone.
Synthesis of chromans via [3 + 3] cyclocoupling of phenols with allylic alcohols using a Mo/o-chloranil catalyst system
Yamamoto, Yoshihiko,Itonaga, Kouhei
scheme or table, p. 717 - 720 (2009/08/19)
(Chemical Equation Presented) The combination of a molybdenum complex (CpMoCl(CO)3 or [CpMo(CO)3]2) and o-chloranil was used as a catalyst in the [3 + 3] cyclocoupling of phenols and allylic alcohols under microwave heating conditions. Substituted chromans were selectively obtained in moderate to good isolated yields.
A novel method for the synthesis of substituted benzochromenes by ethylenediamine diacetate-catalyzed cyclizations of naphthalenols to α,β-unsaturated aldehydes. Concise synthesis of the natural products lapachenole, dihydrolapachenole, and mollugin
Yong, Rok Lee,Yun, Mi Kim
, p. 2401 - 2413 (2008/03/29)
A new synthetic route for biologically interesting benzochromenes was developed starting from naphthalenols and α,β-unsaturated aldehydes in the presence of ethylenediamine diacetate. This methodology was applied for the total synthesis of the biologicall
Convenient Syntheses of Naturally Occurring Angular and Linear Naphthopvrans
Paradkar, Madhusudan V.,Godbole, Himanshu M.,Ranade, Anup A.,Joseph, Augustine R.
, p. 318 - 319 (2007/10/03)
A convenient synthesis of naturally occurring angular naphthopyrans and their 6-demethoxy derivatives is described starting from 2-acetyl-1-naphthols along with the synthesis of linear naphthopyrans from 3-acetyl-2-naphthol.
