Hexahydro-1H-Isoindolinone-Like Scaffolds from Electronically Deactivated and Sterically Hindered Dienes: Synthesis in the Context­ of Muironolide A

Abstract

Initial synthetic efforts toward muironolide A based upon an intramolecular Diels-Alder strategy were hampered by a conjugate reduction rather than the desired half-reduction. An intermolecular Diels-Alder strategy was initiated that utilized electronically deactivated and sterically hindered dienes. The [4+2] cycloadditions were successful, but only with highly reactive dipolarophiles such as N-phenylmaleimide and 4-phenyl-1,2,4-triazoline-3,5-dione thus establishing the scope of these dienes. Although limited, installation of the α,β-unsaturated lactam embedded in the hexahydro-1H-isoindolinone is noteworthy.

Zwitterionic fluorinated detergents: From design to membrane protein applications

“…N-(Benzyloxycarbonyl)allylamine (1). Compound 1 was synthesized according to the procedure described by Olson et al [22] Allylamine (0.56 g, 9.81 mmol, 1.0 equiv) was dissolved in H 2 O (15 mL) and K 2 CO 3 (4.75 g, 34.34 mmol, 3.5 equiv) was added. The mixture was stirred at room temperature for 5 min and then AcOEt (15 mL) was added and the solution was cooled down at 0 C. Benzyl chloroformate (1.4 mL, 9.81 mmol, 1.0 equiv) was added over a period of 15 min and the reaction mixture was stirred at room temperature for 3 h. Then, the organic layer was separated, washed with a 10% HCl solution (2 Â ) and brine, dried over anhydrous Na 2 SO 4 , filtered, and concentrated under reduced pressure.…”

“…The amino function of allylamine was first protected with a carboxybenzyl group according to the procedure described by Olson et al [22] to obtain 1 in 56% yield. The fluorinated chain was then introduced on the allyl moiety by radical addition of perfluorohexyliodide with the use of triethylborane in the presence of oxygen as described by Takeyama and co-workers [35].…”