Total Synthesis of (±)‐Physovenine

Abstract

The Wittig olefination–Claisen rearrangement protocol was applied to the total synthesis of (±)‐physovenine. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

Efficient access to aliphatic esters by photocatalyzed alkoxycarbonylation of alkenes with alkyloxalyl chlorides

“…Furoindoline moiety is broadly found in the core structure of biologically active compounds and natural products [37][38][39][40][41][42][43][44] . Considering that oxindole-3-acetates are versatile building blocks for constructing heterocycle-fused indolines 45,46 , we decided to apply the above method to the preparation of furoindoline derivatives.…”

Unified Approach to Fused and Spirocyclic Oxindoles through Lewis‐Acid‐Promoted Opening of Spiroepoxyoxindoles with Allylsilanes: Application to the Formal Synthesis of (±)‐Physovenine

“…Displacement of the tosylate using NaI, under reflux in butanone, gave the iodo compound, which was then subjected to hydrogenation without any purification to give final intermediate 7 in 75 % yield over two steps. In two more steps, intermediate 7 could be transformed into (±)‐physovenine, thus completing the formal synthesis of target molecule 9 in five steps with an overall yield of 30 %, starting from spiroepoxyoxindole 3a .…”

Efficient Access to Aliphatic Esters by Photocatalyzed Alkoxycarbonylation of Alkenes

“…Additionally, N-(4methoxyphenyl)-N-methylmethacrylamide reacted with ethyl chlorooxoacetate 2a under the standard conditions, giving rise to the desired tricyclic furoindoline 9m, which could be readily converted into bioactive alkaloid physovenine in two steps. 35,36 In contrast to previous reports for the synthesis of physovenine, including Sharpless epoxidation, 37 Grignard reaction, 38 Diels-Alder reaction, 39 catalytic asymmetric Heck reaction, 40 intramolecular Michael addition, 41 [3,3]-sigmatropic rearrangement, 42 this method was better in the atom-and step-economic.…”

“…Furoindoline moiety is broadly found in the core structure of biologically active compounds and natural products. [35][36][37][38][39][40][41][42] Considering that oxindole-3-acetates are versatile building blocks for constructing heterocycle-fused indolines, 43,44 we decided to apply the above method to the preparation of furoindoline derivatives. As shown in Table 3, by treatment of N-arylacrylamides 7 and ethyl chlorooxoacetate 2a under the optimal conditions, followed by reduction with LiAlH 4 at 0 o C, furoindolines 9 were obtained as expected with excellent diastereoselectivities.…”