483-27-2Relevant articles and documents
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.
