Facile Syntheses of (±)-Curcuphenol, (±)-Curcudiol, (±)-Curcuhydroquinone,and (±)-Curcuquinone

The syntheses of (±)-curcuphenol 1, (±)-curcudiol 2, (±)-curcuhydroquinone 3, and (±)-curcuquinone 4 have been achieved. The key steps involved in the syntheses were the Reformatsky reaction and hydrogenation reaction.     

Total synthesis of (±)-maistemonine, (±)-stemonamide, and (±)-isomaistemonine

A full account of the total synthesis of (±)-maistemonine, (±)-stemonamide, and (±)-isomaistemonine is presented. Two approaches have been developed to construct the basic pyrrolo[1,2-a]azepine core of the Stemona alkaloids, featuring a tandem semipinacol/Schmidt rearrangement of a secondary azide and a highly stereoselectively desymmetrizing intramolecular Schmidt reaction, respectively. To build the common spiro-γ-butyrolactone, a new protocol was carried out by utilizing an intramolecular ketone-ester condensation as the key transformation. The vicinal butyrolactone moiety of (±)-maistemonine was stereoselectively introduced via a one-pot procedure involving the epimerization at C-3 and carbonyl allylation/lactonization. Moreover, (±)-stemonamide was divergently synthesized from a common intermediate, and (±)-isomaistemonine was obtained via the epimerization of (±)-maistemonine at C-12.     

Photochemical Synthesis of Aporphines: (±)-Glaucine, (±)-Norglaucine and (±)-Dehydronorglaucine

Photochemical cyclization of 3 afforded 5, 4 and 8.5 on LAH reduction furnished (±)-glaucine (6) and on treatment with ethanolic HCl afforded (±)-norglaucine (7). 10 obtained by the photocyclization of 9 was converted into 7 and 11 via 12.     

Total Synthesis of (±)-Boschnialactone and (±)-Tetrahydroanhydrodesoxyaucubigenin

A total synthesis of (±)-boschnialactone ( 1 ) and (±)-tertahydroanhydrodesoxyaucubigenin ( 2 ) is described and trisubstitued cyclopentenoid 3 is a key intermediate.     

(±)Modhephene and (±)isocomene via cascade rearrangement

Dispiro[3.0.4.2] undecane 1 has been synthesized and rearranged to (±)modhephene 2 and triquinane 3 under kinetic control, and to (±)isocomene 4 and triquinane 5 under thermodynamic control. Molecular mechanics calculations (MM2) support the mechanism proposed.     

Total synthesis of (±)-maistemonine and (±)-stemonamide

The first total synthesis of polycyclic Stemona alkaloid maistemonine has been achieved. The efficient approach features a stereoselective intramolecular Schmidt reaction, a ketone-ester condensation, and a Reformatsky reaction. Additionally, another Stemona alkaloid stemonamide was divergently synthesized from a common intermediate.     

Enzymatic resolution of (±)-cis- and (±)-trans-1-aminoindan-2-ol and (±)-cis- and (±)-trans-2-aminoindan-1-ol

Pseudomonas cepacia lipase (PSL) efficiently catalyses the kinetic resolution of (±)-cis- and (±)-trans-1-aminoindan-2-ol through the O-acylation reaction of the corresponding N-benzyloxycarbonyl derivative using vinyl acetate as the acyl donor. In a similar way, cis-N-Cbz-2-aminoindan-1-ol is resolved when isopropenyl acetate is used as the acylating agent. The enantioselectivity of the reaction was lower for (±)-trans-N-Cbz-2-aminoindan-1-ol due to the different steric requirements for the two conformers of this substrate.     

The total synthesis of (±)-myo-inositol-1,3,4-trisphosphate, (±)-myo-inositol-2,4,5-trisphosphate and (±)-myo-inositol-1,3,4,5-tetrakisphosphate

A total synthesis of (±)-myo-Inositol-1,3,4-Trisphosphate, (±)-myo-Inositol-2,4,5-Trisphosphate and (±)-myo-Inositol-1,3,4,5-Tetrakisphosphate is described.     

Total syntheses of (±)-securinine and (±)- allosecurinine

Total syntheses of (±)-securinine and (±)-allosecurinine that employ a tandem rhodium carbenoid-initiated Claisen/α-ketol rearrangement sequence as a key step are described.     

The Total Synthesis of (±)-Hinesol and (±)-Agarospirol

Eversinceβ-vetivoneanditscongenerswererecognizedtohavespiro[4,5]decaneratherthanthehydroazuleneskeleton,[1]themembersofthisclasshavebecomeafavoritetargetforsynthesis.Herein.weshowafacileconversionofthemajorphotoproductformedinthereactionofmethyl2,4-dioxopentancate(1)with1,5-dimethyl-6-methylenecyclochexene(2)[2]intovetispiranederivatives,hinesol(3),ametaboliteofAtractylodeslancea[3,4],andagarospirol(4)foundinAquilariaagollocha,[5]inracemicforms,respectively.WhenanEtoAsolutionof1and2wasintema…     

Synthetic methods for (Exo,Exo)- and (Exo-,Endo)-2,6-Diarylbicycio [3:3:0] octane lignans: Syntheses of (±)-aptosimon, (±)- styraxin, (±)- asarinin,and (±)- pluviatilol

Short practical syntheses are reported of the title lignans (9a) , (9c) , (13a), and (13b).     

Rhodium(III)-Catalyzed Intramolecular Annulation through CH Activation: Total Synthesis of (±)-Antofine, (±)-Septicine, (±)-Tylophorine, and Rosettacin

Annulation: The efficient synthesis of 3-hydroxyalkyl isoquinolones and 6-hydroxyalkyl 2-pyridones is enabled through the intramolecular annulation of alkyne-tethered hydroxamic esters (see scheme, Cp*=pentamethylcyclopentadienyl). The reaction features high regioselectivity, broad substrate scope, and excellent functional-group tolerance, proceeds under mild reaction conditions with low catalyst loading, and obviates the need for an external oxidant.     

An Expeditious Total Synthesis of (±)-Sempervirol, (±)-Sugiol and (±)-Xanthopherol Methyl Ether by Acid-Catalyzed Cyclialkylation Route

An expeditious total synthesis of (±)-sempervirol (7) (±)-sugiol (8), and (±)-xanthopherol methyl ether (9) by extension of a simple general route is described. The stereochemical results of the cyclialkylation of 2-(2-p) and (2-m-isopropylphenylethyl)-1,3,3-trimethylcyclohexanols (1e) and (1f) follow the general pattern observed earlier.     

Stereocontrolled total synthesis of (±)-norpatchoulenol and two metabolites of patchouli alcohol, (±)-hydroxy patchouli alcohol and the corresponding (±)-carboxylic acid

The first total synthesis of the two biooxidation products of patchouli alcohol (2), (±)-hydroxy patchouli alcohol (3) and the corresponding (±)-carboxylic acid 4, has been achieved in highly stereoconcrolled manners. Synthesis of (±)-norpatchoulenol (1), the real odoriferous substance of patchouli oil, has been accomplished by the biogenetic route via (±)-3 and (±)-4.