20213-26-7Relevant articles and documents
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.
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.
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