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1.
The total synthesis of natural antitumor agent (±) peperomin A, B and C are reported. These syntheses were started from benzophenones and diethyl succinate by Stobbe condensation. Three successive steps were employed to give the (±)-peperomins. 相似文献
2.
A process for the synthesis of (±)-isodeoxypodophyllotoxin starting from ethyl 3,4-methylcnedioxy-benzoacetate and methyl 3,4,5-trimethoxycinnamate is described. 相似文献
3.
A total synthesis of (±)-patriscabrol (1) and (±)-boschnialactone (2) is described. The cyclopentapyranone skeleton is assembled by means of Baeyer-Villiger oxidation of ketol 5. 相似文献
4.
Attila Moricz Elisabeth Gassmann Stefan Bienz Manfred Hesse 《Helvetica chimica acta》1995,78(3):663-669
In the synthesis of the title compound 12 , the important intermediate 7 was obtained in good yield from the easily available ethyl 5, 5-ethylenedioxy-2-oxocyclohexane-1-carboxylate ( 1 ) via ring enlargement of the bicyclic enol ether 5 (Scheme). Its reduction (NaBH4 in EtOH) and subsequent protection with (t-Bu)Me2Si resulted in the highly functionalized ten-membered lactone 9 . Introduction of the (Z)-configurated double bond, followed by deprotection and elimination of H2O, gave (±)-pyrenolide B ( 12 ) in 16% overall yield. 相似文献
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6.
A total synthesis of (±)-iridolactone ( 1 ) from bicyclo[2.2.1]ketone 6 is described. Trisubstituted cyclopentenoid aldehyde 7 is a key intermediate. 相似文献
7.
Emil R. Koft 《Tetrahedron》1987,43(24):5775-5780
The naturally occurring hypotensive agent barbatusol (1a) has been synthesized in racemic form from 3-isopropylveratrole and 4,4-dimethyl-2-cyclohexene-1-one. An improved procedure for deprotection of barbatusol dimethyl ether (1b) is described. 相似文献
8.
Andrew Madin Christopher J. O'Donnell Taeboem Oh David W. Old Larry E. Overman Matthew J. Sharp 《Angewandte Chemie (International ed. in English)》1999,38(19):2934-2936
A complex molecular reorganization ( 1 → 2 ), a sequential anionic aza-Cope rearrangement and Mannich cyclization, and an unprecedented intramolecular Heck reaction of the tetrasubstituted double bond of a vinylogous carbamate are key steps in a new total synthesis of (±)-gelsemine ( 3 ). MOM=methoxymethyl, DBU=1,8-diazabicyclo[5.4.0]undec-7-ene. 相似文献
9.
Yasuo Ohta Takashi Okamoto Masumi Tamura Matsumi Doe Yoshiki Morimoto Takamasa Kinoshita Kazuo Yoshihara 《Journal of heterocyclic chemistry》1998,35(2):485-487
The title compounds were efficeintly synthesized from 3-fuancarboxylic acid via the Birch recuction-elimination. 相似文献
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11.
0(26)-Methyl-28,29-bisnor-(±)-kijanolide (23) has been synthesized via aldol reaction of spirotetronate 3 with octahydronaphthalene aldehyde 4 and subsequent macrocyclization of the resulting product. 相似文献
12.
(±)-Muscone ((±)-1) has been synthesised in three steps from 2-(2′-methylprop-2′-enyl)cyclododecan-1-one ( 2 ). The synthesis involves two key transformations: a Lewis-acid-mediated intramolecular ene reaction ( 2→3 ) and the β-cleavage of the bicyclic potassium alkoxide 3a′ to the macrocyclic enone (Z)- 11 . 相似文献
13.
(±)-Latifolin dimethyl ether has been synthesized by coupling 1,2,4-trimethoxybenzene and o-methoxycinnamyl cation. The isomeric benzylstyrene is also a product of the reaction. Among the possible biogenetic routes for the related compounds present in Dalbergia latifolia the most likely steps seem to be phenylcinnamic esters and 4-phenylcoumarins followed by stages of reduction. The alternative of cinnamyl cation functioning will limit the biosynthesis only to latifolin type of compounds. 相似文献
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15.
The total synthesis of (±)-carnphor and (±)-epicamphorenone from methylcyclopentadiene are described. 相似文献
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17.
(±)-2-Pupukenone ( 4 ) has been synthesized, the key step being the intramolcular Diels-Alder reaction of the intermediate 13 to 14 (42%) and 15 (14%). The bromodiene 12 has been obtained from the reaction of α-isopropylidene-γ-lactone (Scheme 2) 12 with sodium phenylselenide and subsequent esterification to 9 , oxidation and thermal elimination of which furnished 10 . Reduction of 10 with diisobutylaluminimum hydride and treatment of the resulting alcohol 11 with PBr3 led to the required bromodiene 12 . Finally, hydrogenation of the 14 on Pt(C) in CH3OH gave a 4:1 mixture of 2-pupukeanone ( 4 ) and epi-2-pupukeanone 16 . 相似文献
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19.
A facile novel synthesis of (±)-O-methylcannabichromene ( 5d ) together with (±)-2-methyl-2-(4-methyl-3-pentenyl)-5-methoxy-2H-benzopyran ( 5a ) and its 7-methyl ( 5b ) and 7-propyl ( 5c ) homologues, using organolithium salts is described. 相似文献