55903-44-1Relevant articles and documents
Synthetic studies on indole alkaloids. VI synthesis of tetrahydroakuammicine and dihydrocorynantheol via 2-(3-indolyl)-4-piperidones
Diez,Vila,Sinibaldi,Troin,Rubiralta
, p. 733 - 736 (1993)
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
Convenient synthesis of the key intermediate for dihydrocorynantheol and protoemetinol from the monoacetate of 4-cyclopentene-1,3-diol
Kobayashi, Yuichi,Yagi, Kaori,Kaneko, Yuki
, p. 1541 - 1548 (2011/05/05)
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.
A divergent strategy for the synthesis of secologanin derived natural products
English, Brandon J.,Williams, Robert M.
supporting information; experimental part, p. 7869 - 7876 (2011/02/21)
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.
General strategy for the syntheses of corynanthe, tacaman, and oxindole alkaloids
Deiters, Alexander,Pettersson, Martin,Martin, Stephen F.
, p. 6547 - 6561 (2007/10/03)
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.
SYNTHESES OF (+/-)-Z-GEISSOSCHIZOL, (+/-)-3-EPI-Z-GEISSOSCHIZOL, (+/-)-CORYNANTHEIDOL, (+/-)-DIHYDROCORYNANTHEOL, (+/-)-3-EPI-DIHYDROCORYNANTHEOL AND THE CORRESPONDING CORYNAN-17-OIC ACID METHYL ESTERS
Lounasmaa, Mauri,Jokela, Reija,Tirkkonen, Birgit,Miettinen, Jari,Halonen, Minna
, p. 321 - 339 (2007/10/02)
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.
New approaches to Corynanthe alkaloids involving the conjugate addition of dialkyl malonates to unsaturated thiolactams: Synthesis of (±)-3-epi-dihydrocorynantheol
Gomez-Pardo,Desmaele,D'Angelo
, p. 6633 - 6636 (2007/10/02)
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.
SHORT SYNTHESIS OF (+/-)-CORYNANTHEIDOL AND (+/-)-3-EPICORYNANTHEIDOL
Lounasmaa, Mauri,Jokela, Reija
, p. 1351 - 1358 (2007/10/02)
A short synthesis for (+/-)-corynantheidol and (+/-)-3-epicorynantheidol is described.
A Stereoselective Total Synthesis of (+/-)-Dihydrocorynantheol via Radical Cyclisation
Ihara, Masataka,Taniguchi, Nobuaki,Fukumoto, Keiichiro,Kametani, Tetsuji
, p. 1438 - 1439 (2007/10/02)
Stereoselective total synthesis of (+/-)-dihydrocorynantheol (1) has been accomplished via radical cyclisation of a bromoacetal (9) of a homoallylic alcohol.
Stereoselective Total Synthesis of (+/-)-Hirsutine and Related Corynanthe Alkaloids
Brown, Richard T.,Jones, Martin F.,Wingfield, Mark
, p. 847 - 848 (2007/10/02)
In a completely stereoselective sequence, an analogue of dihydrosecologanin aglucone has been synthesised via a novel cyclopentenedione dimer and converted into tetracyclic indole alkaloids.
A Specific and Efficient Synthesis of (+/-)-Dihydrocorynantheol
Danieli, Bruno,Lesma, Giordano,Palmisano, Giovanni,Tollari, Stefano
, p. 1237 - 1240 (2007/10/02)
A specific and efficient synthesis of (+/-)-dihydrocorynantheol (1) is reported.Starting with the easily accessible imine (3), ring D was built via stereoselective reaction with the lactone (4a), thus providing the complete carbon skeleton of (1); subsequ
