7679-52-9

Upstream product

• 50-00-0 formaldehyd 
• 712281-00-0 (3aR,6S,7aS)-6-(tert-butyldimethylsilyloxy)-3a,6,7,7a-tetrahydro-3a-[3',4'-(methylenedioxy)phenyl]indoline 
• 17680-04-5 (3,4-methylenedioxy)phenylmagnesium bromide 
• 7700-86-9 (+/-)-oxo-crinine 
• 15930-53-7 6-bromo-3,4-methylenedioxybenzaldehyde 

Downstream Products

• 468-22-4 buphanisine 
• 510-67-8 (+/-)-crinine 
• 510-67-8 (+/-)-crinine 
• 510-67-8 epicrinine 

Relevant academic research and scientific papers

Asymmetric total synthesis of gracilamine and determination of its absolute configuration

(+)-Gracilamine, a biologically attractive and structurally unique pentacyclic Amaryllidaceae alkaloid, was biomimetically synthesized in 11 linear steps in 9.9% overall yield from the known racemic oxocrinine. The synthesis features an asymmetric hydrogenation, a ring-opening/benzylic oxidation/cyclization sequence, and a biomimetic intramolecular cycloaddition. This total synthesis not only allows the assignment of its absolute configuration, but also provides experimental support for the hypothesis that naturally occurring (+)-gracilamine is biogenetically derived from the crinine-type alkaloid (+)-epivittatine.

Asymmetric synthesis method for crinum asiaticum alkaloid

The invention relates to an asymmetric synthesis method for crinum asiaticum alkaloid taking the asymmetric catalytic hydrogenation reaction as the key step. According to the method, through racemic asymmetric catalytic hydrogenation kinetic resolution for replacing cyclohexanone, quick asymmetric synthesis for 22 kinds of crinum asiaticum alkaloid comprising (-)-crinine, (+)-epivittatine, (+)-vittatine, (-)-epicrinine and the like and eight analogues is achieved concisely and efficiently.

Catalytic Asymmetric Total Syntheses of Naturally Occurring Amarylidaceae Alkaloids, (-)-Crinine, (-)- epi-Crinine, (-)-Oxocrinine, (+)- epi-Elwesine, (+)-Vittatine, and (+)- epi-Vittatine

An expeditious approach to catalytic enantioselective total syntheses of crinine-type Amaryllidaceae alkaloids has been accomplished via a Pd-catalyzed enantioselective decarboxylative allylation of allylenol carbonates as a key step (up to 96% ee). Using this strategy, collective total syntheses of Amaryllidaceae alkaloids such as (-)-epi-elwesine (1b), (-)-crinine (1c), (-)-epi-crinine (1e), (-)-oxocrinine (1f), and (-)-buphanisine (1d) have been accomplished. Gratifyingly, naturally occurring Amaryllidaceae alkaloids such as (+)-vittatine (1g), (+)-epi-vittatine (1h), and (+)-epi-elwesine (1i) [enantiomers of (-)-1c, (-)-1e, and (-)-1b, respectively] have also been achieved by switching the antipode of ligand used in the catalytic enantioselective step.

Synthesis of biologically active natural products by [3?+?2] cycloaddition of non-stabilized azomethine ylides (AMY): Concepts and realizations

Non-stabilized azomethine ylides (AMY) which are represented as a zwitterionic form of a C[sbnd]N[sbnd]C unit having four electrons in three parallel atomic π orbitals perpendicular to the plane of the dipole, undergoes 1,3-dipolar cycloaddition to produc

Bioinspired enantioselective synthesis of crinine-type alkaloids: Via iridium-catalyzed asymmetric hydrogenation of enones

A bioinspired enantioselective synthesis of crinine-type alkaloids has been developed by iridium-catalyzed asymmetric hydrogenation of racemic cycloenones. The method features a biomimetic stereodivergent resolution of the substrates bearing a remote arylated quaternary stereocenter. Using this protocol, 24 crinine-type alkaloids and 8 analogues were synthesized in a concise and rapid way with high yield and high enantioselectivity.

A through intra-molecular to aromatization and efficient synthesis of the wenshu blue alkali and its analogue (by machine translation)

The present invention provides a through the intramolecular to aromatization and efficient synthesis of the wenshu blue alkali and analogues thereof, comprises the following 7 steps: aniline compound synthesis, synthesis of aniline compound, phenol compound synthesis, synthesis of cyclized product, two alcoholic compound synthesis, the synthesis of the compounds, grand crinum alkali and analogs thereof. The invention by transition metal-catalyzed coupling reaction in the molecule to aromatization similar biological pathways, while at the same time realize superior chemical and enantiomeric selectivity, this is biological synthesis the incomparable. This synthetic route step is short, and the product yield is high. (by machine translation)

Efficient syntheses of (-)-crinine and (-)-aspidospermidine, and the formal synthesis of (-)-minfiensine by enantioselective intramolecular dearomative cyclization

Polycyclic alkaloids bearing all-carbon quaternary centers possess a diversity of biological activities and are challenging targets in natural product synthesis. The development of a general and asymmetric catalytic method applicable to the efficient syntheses of a series of complex polycyclic alkaloids remains highly desirable in synthetic chemistry. Herein we describe an efficient palladium-catalyzed enantioselective dearomative cyclization which is capable of synthesizing two important classes of tricyclic nitrogen-containing skeleton, chiral dihydrophenanthridinone and dihydrocarbazolone derivatives bearing all-carbon quaternary centers, in excellent yields and enantioselectivities. The P-chiral monophosphorus ligand AntPhos is crucial for the reactivity and enantioselectivity, and the choice of the N-phosphoramide protecting group is essential for the desired chemoselectivity. This method has enabled the enantioselective total syntheses of three distinctive and challenging biologically important polycyclic alkaloids, specifically a concise and gram-scale synthesis of (-)-crinine, an efficient synthesis of indole alkaloid (-)-aspidospermidine and a formal enantioselective synthesis of (-)-minfiensine.

Construction of the 5,10b-phenanthridine skeleton using [3+2]-cycloaddition of a non-stabilized azomethine ylide: Total synthesis of (±)-maritidine and (±)-crinine alkaloids

Vicinal quaternary and tertiary stereocenters of the 5,10b-phenanthridine skeleton 1 are constructed simultaneously in one step by the [3+2]-cycloaddition of non-stabilized azomethine ylide 9, generated by sequential double desilylation of 10 utilizing silver(I) fluoride as a one-electron oxidant. The regio- as well as stereochemical origin of this cycloaddition reaction is explained through a favorable transition state 9″. The strategy is successfully applied for the total synthesis of the biologically active alkaloids (±)-maritidine (1a), (±)-crinine (1b), and their analogues (1d, 1e, and 1f). The synthesis features construction of the BD ring with concomitant installation of a quarternary and tertiary carbon in a single operation by employing intramolecular 1,3-dipolar cycloaddition of a non-stabilizedazomethine ylide. Oxo-maritidine and oxo-crinine were found to be advanced and efficient intermediates for the synthesis of natural products of this class.

Concise total synthesis of (±)-crinine

The concise total synthesis of (±)-crinine was accomplished in 24% overall yield and eleven steps starting from an easily available allylic alcohol. The key step of the current synthesis involved the NBS-promoted semipinacol rearrangement reaction of ally

Total syntheses of (±)-crinine, (±)-crinamine, and (plusmn;)-6a-epi-crinamine via the regioselective synthesis and Diels-Alder reaction of 3-aryl-5-bromo-2-pyrone

(Chemical Equation Presented) We have devised a new unified synthetic protocol to (±)-crinine, (±)-crinamine, and (±)-6a-epi- crinamine from the Diels-Alder cycloadduct of 3-(3,4-methylenedioxyphenyl)-5- bromo-2-pyrone with TBS vinyl ether. The requisite 3-(3,4-methylenedioxyphenyl)- 5-bromo-2-pyrone was prepared from the C3-selective Stille coupling reaction of 3,5-dibromo-2-pyrone. Also noted is that the vinyl bromide can be used as a handle for further derivatization.