Total synthesis of (3R, 4S)-4-hydroxylasiodiplodin

Abstract

An alternative and concise total synthesis of (3?R, 4S)-4-Hydroxylasiodiplodin has been reported from inexpensive and commercially available 6-heptenal and Orsellinic acid starting materials. The key steps involved in the synthesis are Wittig reaction, Sharpless epoxidation, Yamaguchi esterification and ring-closing metathesis (RCM).     

An alternative total synthesis of Patulolide A

A new total synthesis of [R]‐Patulolide A from readily available (R)‐propylene epoxide obtained using the asymmetric synthetic approach is reported. The key reactions involved are ozonolysis and Yamaguchi macrolactonization, resulting in the ring system.     

An alternative stereoselective synthesis of greensporone C

Greensporone C, a new 14-membered resorcylic acid lactone, has been synthesized from inexpensive and commercially available starting materials. This convergent synthesis utilizes Cross metathesis using the Grubbs Hoveyda catalyst, alkylation of 1,3-dithiane and Yamaguchi macrolactonization as key steps.     

The first stereo selective total synthesis of (3R),(5R)-5-hydroxy-de-O-methyllasiodiplodin and its epimer via an RCM protocol

The first total synthesis of (3R),(5R)-5-hydroxy-de-O-methyllasiodiplodin and its epimer is reported from malic acid. The adopted approach is highly convergent and stereoselective. The strategy utilizes syn selective reduction and ring-closing metathesis as key steps.     

Synthesis and structure of 1-(4-chlorophenyl)-3-(5-methyl-1, 3-dioxan-5-yl)-(1,2),(3,4)-diepoxybutane

The synthesis and X-ray structural study of 1-(4-chlorophenyl)-3-(5-methyl-1,3-dioxan-5-yl)-(1,2), (3,4)-diepoxybutane are described.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 715–718, April, 1995.     

A new synthetic strategy for catechin-class polyphenols: concise synthesis of (-)-epicatechin and its 3-O-gallate

Concise synthesis of (-)-epicatechin and its 3-O-gallate is described, illustrating efficacy of the new strategy for catechin-class polyphenols based on assembly of lithiated fluorobenzene and epoxy alcohol followed by a pyran cyclization. 1,3,5-Trifluorobenzene serves as the A-ring equivalent for functionalization and the pyran annulation.     

Modified synthesis of methyl (1R,2R,3E,5R)-3-(hydroxyimino)-5-methyl-2-(1-methylethyl)-cyclohexanecarboxylate from (R)-4-menthen-3-one

A modified stereospecific synthesis of potentially biologically and pharmacologically active methyl (1R,2R,3E,5R)-3-(hydroxyimino)-5-methyl-2-(1-methylethyl)cyclohexanecarboxylate from (R)-4-menthen-3-one was developed using sequential 1,4-conjugate addition of Norman reagent catalyzed by CuI?CBF₃?Et₂O?CCuCl₂ and ozonolysis?Creduction of the intermediate (R,R,R)-vinylmenthone by hydroxylamine hydrochloridein MeOH.     

New route to (3RS) (5R) (5-2H)- and (3RS) (5S) (5-2H)-mevalonolactones

The synthesis of mevalonolactone stereospecifically labeled at carbon 5 is described combining chemical reactions with an enzymatic reduction step.     

An alternative approach to 3-(diphenylphosphino)hexahelicene

3-(Diphenylphosphino)hexahelicene is synthesised in good yield and purity, via a three-step sequence involving a palladium-catalysed Mizoroki-Heck coupling reaction and classical oxidative photocyclisation. Mononuclear ruthenium and palladium complexes of 3-(diphenylphosphino)hexahelicene are prepared and characterised.     

An Alternative Approach to Mevinic Acid Analogues from Methyl (3R)-3-Hydroxy-5-Hexenoate and an Extension to Rational Syntheses of (+)-(6R)-Goniothalamin and its Non-natural (-)-(6S)-Enantiomer

The chiral mevinic acid analogues [(15) and (16)] have been prepared from the yeast reduction product (2) by homologation and selenolactonistion and subsequently converted into both enantiomers of Goniothalamin [(17) and (18)].     

Optically active antifungal azoles. IX. An alternative synthetic route for 2-[(1R,2R)-2-(2,4-difluorophenyl)-2-hydroxy-1-methyl-3-(1H-1,2,4- triazol-1-yl)propyl]-4-[4-(2,2,3,3-tetrafluoropropoxy)phenyl]- 3(2H,4H)-1,2,4-triazolone and its analogs

A new route for the synthesis of the optically active antifungal azole TAK-187, 2-[(1R,2R)-2-(2,4-difluorophenyl)-2-hydroxy-1-methyl-3-(1H-1,2,4-tria zol-1- yl)propyl]-4-[4-(2,2,3,3-tetrafluoropropoxy)phenyl]-3(2H,4H)-1,2,4 - triazolone, was established. The key synthetic intermediate, 2-[(1R)-2-(2,4-difluorophenyl)-2-oxo-1-methylethyl]-4-[4-(2,2,3,3- tetrafluoropropoxy)phenyl]-3(2H,4H)-1,2,4-triazolone (8), was prepared starting from the esters (11a, b) of (S)-lactic acid in a stereocontrolled manner. This optically active propiophenone derivative 8 was converted to the one carbon-elongated (1R,2S)-diol 7, which was then reacted with 1H-1,2,4-triazole to yield TAK-187. This newly developed route was applied to the synthesis of the analogs (25a, b--28a, b) containing an imidazolone or imidazolidinone nucleus.     

从(-)-莽草酸出发合成(3R,5R)-3,4,5-三苯甲酰氧基环己酮

报道了一种合成手性中间体(3R,5R)-3,4,5-三羟基环己酮的新方法。首次以(-)-莽草酸为起始原料,经苯甲酰化、双键氢化、选择性还原甲酯、羟基碘代、碘代烃消除、双键双羟化、片哪醇断裂等步骤,以44.9%的总收率合成了(3R,5R)-3,4,5-三苯甲酰氧基环己酮,所有化合物的结构经¹H NMR、 ¹³C NMR、 IR及MS等确证。      

Methyl (3R,5R)-3,5-dihydroxydecanoate in the asymmetric synthesis of Idea Leuconoe pheromone and formal syntheses of (+)-(3R,5R)-3-hydroxydecano-5-lactone, verbalactone, and Tolypothrix pentaether

A simple and efficient asymmetric synthesis of (5S,7R)-7-hydroxydodecano-5-lactone, a component of the giant danaine butterfly Idea leuconoe pheromone, and formal syntheses of (+)-(3R,5R)-3-hydroxydecano-5-lactone, verbalactone, and Tolypothrix pentaether have been accomplished starting from methyl (3R,5R)-3,5-dihydroxydecanoate. The latter is obtained from methyl 3-[(tributylstannyl)methyl]but-3-enoate using Keck allylation in the key step of the construction of its carbon skeleton.     

An efficient synthetic approach to 6,5'-(S)- and 6,5'-(R)-cyclouridine

Here we present new routes for the efficient syntheses of 6,5'-(S)- and 6,5'-(R)-cyclouridine. The syntheses utilize readily accessible uridine as a starting material. This route to the R diastereomer is significantly more efficient than previous synthetic efforts, allowing us to obtain large amounts of pure material for future biological testing.     

Synthesis of (+)-(3R,5R)-3-Hydroxy-5-decanolide and Massoialactone,and Formal Synthesis of Verbalactone

Total synthesis of (3R, 5R)-(+)-3-hydroxy-5-decanolide (1) and massoialactone (2), and formal synthesis of verbalactone (3), have been reported.     

Crystal Structure of 5-(l-Menthyloxy)-3-Bromo-4-(R)-(+)-Methylbenzylamino-2(5H)-Furanone

１ＩＮＴＲＯＤＵＣＴＩＯＮＳｅｖｅｒａｌｉｍｐｏｒｔａｎｔａｐｐｒｏａｃｈｅｓｔｏｔｈｅｓｙｎｔｈｅｓｉｓａｎｄｐｒｏｐｅｒｔｉｅｓｏｆｃｈｉｒａｌγ ａｌｋｙｌｏｘｙｂｕｔｅｎｏｌｉｄｅｓｈａｖｅａｔｒａｃｔｅｄｍｕｃｈａｔｅｎｔｉｏｎｏｗｉｎｇｔ...