82864-22-0Relevant articles and documents
Efficient one-pot trans-dihydroxylation of 2H-pyrans using dimethyldioxirane (DMD): synthesis of trans-3,4-dihydroxy-3,4-dihydro-O-methyloctandreolones, orixalone D, and trans-3,4-dihydroxy-3,4-dihydromollugin natural products
Wang, Xue,Lee, Yong Rok
, p. 6275 - 6280 (2008/02/10)
An efficient one-pot formation of trans-diols on 2H-pyranyl rings was achieved by dimethyldioxirane in wet acetone. This new methodology was applied to the synthesis of natural products containing trans-diol on the pyranyl rings such as trans-3,4-dihydroxy-3,4-dihydro-O-methyloctandreolones, orixalone D, and trans-3,4-dihydroxy-3,4-dihydromollugin.
Synthesis of models of metabolites: Oxidation of variously substituted chromenes including acronycine, by a porphyrin catalytic system
Akagah, Bernardin,Estour, Francois,Verite, Philippe,Seguin, Elisabeth,Tillequin, Francois,Lafont, Olivier
, p. 1267 - 1272 (2007/10/03)
The influence of chemical neighbouring on oxidation of substituted 2,2-dimethylchromenes derivatives 5-8 by a biomimetic catalytic system was first studied. It was then applied to acronycine an anti-cancer drug in order to obtain in one single step oxidized products resulting from the reactivity of the 1,2-double bond in the pyranic D-ring. These 2,2-dimethylchromenes constitute the structural moiety responsible for the activity of acronycine. This oxidation showed the sensitivity of the ethylenic bond, leading to the formation of the corresponding epoxides, diols and/or ketoalcohol. In the case of 5-dimethylamino-2,2-dimethylchromene 8, the double bond was not sensitive to oxidation, but the N-methyl groups reacted to lead to the formamide derivative 16 and an imino-alcohol 17. This methodology applied to acronycine molecule 1, allowed to obtain in one step, two oxidized compounds, a trans-diol 3 and a ketoalcohol 4 under preparative conditions.
Chemical and enzyme-catalysed syntheses of enantiopure epoxide and diol derivatives of chromene, 2,2-dimethylchromene, and 7-methoxy-2,2-dimethylchromene (precocene-1)
Boyd, Derek R.,Sharma, Narain D.,Boyle, Rosemary,Evans, Timothy A.,Malone, John F.,McCombe, Kenneth M.,Dalton, Howard,Chima, Jagdeep
, p. 1757 - 1765 (2007/10/03)
Procaryotic (bacterial) dioxygenase-catalysed asymmetric dihydroxylation of chromene and 2,2-dimethylchromene to yield the (4S)-enantiomers of the corresponding cis-diols exclusively is reported. The epoxide, and derived cis- and trans-diol products from the previously reported eucaryotic (mammalian) metabolism of precocene-1 (7-methoxy-2,2-dimethylchromene), and the corresponding epoxide and diol derivatives of chromene and 2,2-dimethylchromene, have now been obtained in enantiopure form by chemical resolution of the corresponding bromohydrins using methoxy-(trifluoromethyl)phenylacetic acid (MTPA) or camphanate esters. The absolute configurations of the epoxides, cis- and trans-diols have been determined by chemical synthesis from, and stereochemical correlation with, the corresponding camphanate and MTPA esters. X-Ray crystal structure analysis has provided an unequivocal method for assignment of the absolute stereochemistry in each case.
The Synthesis of the Epoxide and some other possible Metabolites of Precocene I
Jennings, Richard C.,Ottridge, Anthony P.
, p. 1733 - 1738 (2007/10/02)
The synthesis of precocene I epoxide, 3,4-epoxy-7-methoxy-2,2-dimethylchroman (8), is described.This compound is the highly reactive metabolite responsible for the biological effects of the precocenes.The syntheses of some other oxygenated derivatives of precocene I, which are themselves possible metabolites, are also described.
Studies of Chromens. Part 3. Routes to 2,2-Dimethylchroman-3-ones and 4-Ethyoxycarbonyl-2,2-dimethylchromens. Synthesis of a Stable Chromenopyrazolinone
Anastasis, Panayiotis,Brown, Philip E.
, p. 1431 - 1437 (2007/10/02)
2,2-Dimethyl-3,4-epoxychroman (6a) was converted into 2,2-dimethylchroman-3-one which readily underwent ethoxycarbonylation to 4-ethoxycarbonyl-2,2-dimethylchroman-3-one (5c).The derived 4-ethoxycarbonyl-2,2-dimethylchromen (1b) reacted with hydrazine to give the pyrazolidinone (4a), oxidation of which gave the stable pyrazolinone (11).Lead tetra-acetate acetoxylation of 7-methoxy-2,2-dimethylchroman-4-one, followed by metal hydride reduction, afforded the 3,4-diols as a mixture of isomers.The relative proportions of cis and trans isomers could be varied from 1:1 to 5:1, respectively, by the choice of reducing conditions.Acid-catalysed dehydration of the diol mixture gave 7-methoxy-2,2-dimethylchroman-3-one (5b).This was unstable and could not be ethoxycarbonylated, but 4-ethoxycarbonyl-7-methoxy-2,2-dimethylchroman-3-one (5d)/(1j) was obtained by a standard synthesis.
SYNTHESIS, RESOLUTION AND ABSOLUTE CONFIGURATION OF THE DIOL METABOLITES OF PRECOCENE I
Jennings, Richard C.
, p. 2693 - 2696 (2007/10/02)
All four stereoisomers of precocene I 3,4-dihydrodiol have been prepared and their absolute configurations assigned by the exciton chirality method.