Bromopiperonal

Anhydrolycorinone, Hippadine, Kalbretorine, Oxoassoanine, Pralosine. The efficient coupling of 7-stannylated indoline 218 and 6-bromopiperonal promoted by Pd(0) complex provided another route [60] to anhydrolycorinone (201), hippadine (202) and the phenolic alkaloid, kalbretorine (222) [61]. 

Upon investigating the literature, Lauren noted that arylboronic acids substituted with electron-withdrawing groups often experience extensive protodeboronation and poor yields under the standard Suzuki conditions that utilize aqueous NaaCOs as a base. A solution to this problem lies in either the use of a milder base or nonaqueous conditions. Therefore, Lauren chose to employ NaHCOj as a base. The arylboronic acid derivative of 6-bromopiperonal was coupled with the suitably elaborated aryl iodide to provide the desired biaryl ( )-3 in moderate yields (Eq. 15). 

Coehlo and Lopes used a non-traditional approach in their construction of the dihydroisoquinolin5(6H)-core of the amaryllidaceae alkaloid plicamine (103). The MBH reaction was performed between 6-bromopiperonal 106 and methyl aciylate using ultrasound in the presence of the ionic liquid 1-methyl methylimidazolium to deliver the adduct 107 in 80% yield. Again, the MBH reaction provided the requisite functionality to allow further derivatization to afford the dihydroisoquinoline subunit 105 after several chemical steps. 

As shown in Schane 10.35a, this distinct synthesis began with the scalable preparation of benzocyclobntenol silyl ether 178 from 6-bromopiperonal (177) throngh epoxida-tion, cyclization, and silylation procedure [69]. The subsequent thermal cycloaddition of 179, via an o-quinodi-methane intermediate 180, with fumarate-derived amide 181 afforded C—H functionalization precursor 182 albeit in moderate yield and diastereoselectivity. As expected, when this amide is subjected to stoichiometric Pd(OAc)j in hot CHjCN, the Pd" complex 183 was formed in 53% yield. However, upon the exposure of this intermediate with C7 —H activation to excess of 3,4,5-trimethoxyiodobenzene (163) under the usual arylation condition, p-lactam 184 was obtained exclusively in 75% yield, instead of the expected... 

Heliotropine forms a number of well-defined crystalline compounds, which are suitable for its identification. Bromopiperonal... 

Bromo-4,5-methylenedioxy-B-nitrostyrene. A solution of 64 g bromopiperonal, 65 g nitromethane (or analog), and 30 g of NH4OAC in 400 ml of AcOH, is heated to reflux for 2 hours. Cool and pour the mixture into 1 liter of water. This will precipitate a crystal solid that is removed by filtration and recrystallized from CHCf-EtOH (50% by volume) to give the product. Yield 55 g, mp 160-161°. 

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