Preparation of Alkyl-Substituted Indoles in the Benzene Portion. Part 6. Synthetic Procedure for 4-, 5-, 6-, or 7-Alkoxy- and Hydroxyindole Derivatives.
Preparation of Alkyl-Substituted Indoles in the Benzene Portion. Part 6. Synthetic Procedure for 4-, 5-, 6-, or 7-Alkoxy- and Hydroxyindole Derivatives.
Formal Synthesis of (+)- and (−)-Perhydrohistrionicotoxin: A “Double Henry”/Enzymatic Desymmetrization Route to the Kishi Lactam<sup>1</sup>
作者:Frederick A. Luzzio、Richard W. Fitch
DOI:10.1021/jo990293i
日期:1999.7.1
diacetate 2 which was an excellent substrate for esterase-mediated hydrolysis to hydroxyacetate 12. Deoxygenation of 12 using a Barton protocol, followed by Zemplén deacylation and Swern oxidation, gave the (-)-antipode of the Kishi lactam (3). Moffatt oxidation of hydroxyacetate 12 followed by ketal protection and Zemplén deacylation gave ketalalcohol 19. Barton deoxygenation of 19 followed by ketal hydrolysis
Continuous flow based catch and release protocol for the synthesis of α-ketoesters
作者:Alessandro Palmieri、Steven V Ley、Anastasios Polyzos、Mark Ladlow、Ian R Baxendale
DOI:10.3762/bjoc.5.23
日期:——
Using a combination of commercially available mesofluidic flow equipment and tubes packed with immobilised reagents and scavengers, a new synthesis of α-ketoesters is reported.
A new simple and efficient synthesis of 6‐nitroindoles, starting from N‐carboxylalkylpyrrole‐2‐carboxaldehydes and protected β‐nitro ketones, has been developed. The method involves two distinct domino processes, respectively performed underflowchemicalconditions and microwave irradiation. 6‐Nitroindoles were produced in good to excellent overall yields.
Preparation of Alkyl-Substituted Indoles in the Benzene Portion. Part 6. Synthetic Procedure for 4-, 5-, 6-, or 7-Alkoxy- and Hydroxyindole Derivatives.
A novel method for the preparation of indole derivatives that are alkoxy- and hydroxy-substituted in the benzene portion of the indole nucleus is described. The acid-induced cyclization reaction of (arylsulfonyl)pyrrole derivatives (4a, 5b, and 5a) in the presence of an appropriate alcohol gave 4-, 5-, 6-, and 7-alkoxyindole derivatives (13 and 28), respectively, where the alkoxy group was originated from the alcohol employed. As an application of the present method, a short and efficient synthesis of two dopamine agonists (34 and 44) was attained by treating appropriately functionalized pyrrole derivatives (38 and 41) with an acid in the presence of 1, 3-propanediol, followed by deprotection of alkoxy function, and subsequent reduction with lithium aluminum hydride. A reaction mechanism is also suggested for the formation of an unusual product, 4-[2-(diprophlamino)-1-hydroyethyl]-6-hydroxyindole (46) in the reduction of N, N-dipropyl-(6-hydroxy-1-phenylsulfonyl)indole-4-acetamide (40).