483-27-2

Upstream product

• 153-94-6 D-tryptophan 
• 295788-84-0 N_b-(Z-2'-iodo-2'-butenyl)tryptophan benzyl ester 
• 295788-90-8 (2R,3S,6R,12bS)-3-Ethyl-2-methoxycarbonylmethyl-1,2,3,4,6,7,12,12b-octahydro-indolo[2,3-a]quinolizine-6-carboxylic acid benzyl ester 
• 131792-94-4 [(3S,12bS)-3-Ethyl-12-methoxymethyl-3,4,6,7,12,12b-hexahydro-1H-indolo[2,3-a]quinolizin-(2Z)-ylidene]-acetic acid methyl ester 
• 439-69-0 (+/-)-Z-geissoschizol 
• 131697-82-0 2-(2-Acetoxy-ethyl)-3-ethyl-1,6,7,12b-tetrahydro-4H-indolo[2,3-a]quinolizine-12-carboxylic acid tert-butyl ester 
• 131697-78-4 3-Ethyl-4-(2-hydroxy-ethyl)-1-[2-(1H-indol-3-yl)-ethyl]-pyridinium; bromide 

Downstream Products

• 483-27-2 (+/-)-dihydrocorynantheol 

Relevant academic research and scientific papers

Convenient synthesis of the key intermediate for dihydrocorynantheol and protoemetinol from the monoacetate of 4-cyclopentene-1,3-diol

We invented an efficient method to obtain the key δ-lactone possessing the (CH2)2OTBDPS and Et groups at C3 and C4, respectively, starting with the acetate of 4-cyclopentene-1,3-diol, which was subjected to Pd-catalyzed allylation with malonate anion to attach the (CH 2)2OTBDPS group. The Et group was then installed by 1,4-addition to the derived enone. Finally, the resulting enol TMS ether was oxidized to afford the lactone. Furthermore, the lactone was converted to dihydrocorynantheol and protoemetinol, both of which are typical examples of indoloquinolizidine and benzo[α]quinolizine alkaloids. The Japan Institute of Heterocyclic Chemistry.

Organocatalytic approach for the syntheses of corynantheidol, dihydrocorynantheol, protoemetinol, protoemetine, and mitragynine

O-Trimethylsilyl (TMS)-protected diphenylprolinol-catalyzed Michael addition of a functionalized alkylidene malonate and n-butanal affords an aldehyde. This adduct can serve as the common intermediate for the assembly of secologanin tryptamine and dopamin

A divergent strategy for the synthesis of secologanin derived natural products

The syntheses of d,l-geissoschizol, d,l-corynantheidol, d,l-dihydrocorynantheol, d,l-protoemetinol, and d,l-3-epi-protoemetinol have been accomplished from a single synthetic intermediate.

Synthesis of indole alkaloid (-)-corynantheidol and formal synthesis of (-)-corynantheidine via one-pot asymmetric azaelectrocyclization

The highly efficient asymmetric total synthesis of indole alkaloid, (-)-corynantheidol, containing a 2,4,5-trisubstituted piperidine core, was achieved using a new version of the one-pot azaelectrocyclization reaction. The formal synthesis of (-)-corynant

General strategy for the syntheses of corynanthe, tacaman, and oxindole alkaloids

We report herein the total synthesis of the corynanthe alkaloid dihydrocorynantheol and the formal syntheses of the indole alkaloids tacamonine, rhynchophylline, and hirsutine. The strategies for assembling the corynanthe and tacaman skeletal frameworks comprised of both the classical ABD → ABCD and ABC → ABCD approaches wherein the variously substituted piperidinone D-rings were formed via ring-closing metathesis (RCM) followed by a 1,4-addition to introduce the requisite side chain at C(15). Since 1,4-additions to α,β-unsaturated lactams represent an underdeveloped field, we conducted a series of studies with two unsaturated lactams employing organocuprates and metal enolates as the nucleophiles. These studies revealed that organocuprates derived from Grignard reagents and either stoichiometric amounts of CuCN or catalytic amounts of CuBr·DMS complex are excellent nucleophiles for such additions; TMSC1 was a crucial additive for optimizing these reactions. The anion derived from ethyl 1,3-dithiolane-2-carboxylate was also an excellent nucleophile in these 1,4-additions, although the stereochemistry of such 1,4-additions to carboline-derived, unsaturated lactams was sensitive to substitution on the indole nitrogen atom. The ABD → ABCD approach to these alkaloids featured a novel one-pot sequence of an RCM reaction and a zirconocene-catalyzed carbomagnesation followed by a second RCM to generate the D-ring.

Synthetic studies on indole alkaloids. VI synthesis of tetrahydroakuammicine and dihydrocorynantheol via 2-(3-indolyl)-4-piperidones

The synthesis of dihydrocorynantheol (5) and of the pentacyclic Strychnos alkaloid tetrahydroakuammicine (4) is reported from 5-ethyl-N-hydroxyethyl-2-(1-phenylsulfonyl-3-indolyl)-4-piperidineacet ates (1) by means of a K(t)OBu/BF3.Et2/su

SYNTHESES OF (+/-)-Z-GEISSOSCHIZOL, (+/-)-3-EPI-Z-GEISSOSCHIZOL, (+/-)-CORYNANTHEIDOL, (+/-)-DIHYDROCORYNANTHEOL, (+/-)-3-EPI-DIHYDROCORYNANTHEOL AND THE CORRESPONDING CORYNAN-17-OIC ACID METHYL ESTERS

The utility of the Claisen rearrangement using carefully separated, diastereoisomeric allylic alcohols (1a) and (1b) in the preparation of (+/-)-Z-geissoschizol (4a), (+/-)-3-epi-Z-geissoschizol (4b), (+/-)-corynantheidol (7a), (+/-)-dihydrocorynantheol (8a), (+/-)-3-epi-dihydrocorynantheol (8b) and the corresponding corynan-17-oic acid methyl esters (3a, 3b, 5a, 6a and 6b) is shown.Special attention is paid to the stereochemical outcome of catalytic (PtO2) hydrogenation of the C(20) Z-ethylidene side chain.

Recent progress using chiral formamidines in asymmetric syntheses

The ability to generate a carbanion next to nitrogen in a chiral environment has led to a number of useful asymmetric routes to alkaloids and related substances. Mechanistic studies have been conducted to understand the nature of these alkylations.

New approaches to Corynanthe alkaloids involving the conjugate addition of dialkyl malonates to unsaturated thiolactams: Synthesis of (±)-3-epi-dihydrocorynantheol

Addition of dimethyl malonate to thiolactam 8 led to a mixture of Michael adducts 9 and 10 (6:1, respectively). Compound 9 has been converted in 4 steps into (±)-3-epi-dihydrocorynantheol 16.