Naresh K. Nayyar

A short, enantiospecific synthesis of a protected seco acid precursor to (R,R)-(−)-pyrenophorin

Abstract Described herein is a four-step enantiospecific synthesis of a protected seco acid precursor of (R,R)-(−)-pyrenophorin in 23% yield from a chiral β-ketoester 3 , which can be prepared in one step from ethyl acetoacetate by a standard procedure.

Generation of N-acyl iminium ions from ionization-rearrangement reactions of N-triflyloxy amides

Abstract N-Triflyloxy amides undergo ionization in refluxing isopropanol to give N-acyliminium ions which can be trapped by addition of allyltrimethylsilane to the reaction mixture. Alternatively they can be converted to N-(isopropoxy)alkyl amides and then back to N-acyliminium ions under a variety of conditions.