Abstract
12-Hydroxy-9(10→20)-5aH-abeo-abieta-1(10),8(9),12(13)-triene-11,14-dione (quinone 2) served as the dienophile in numerous intermolecular Diels-Alder reactions. These cycloadditions were conducted either thermally (including microwave heating) or with Lewis acid activation. While most dienes reacted with quinone 2 in good chemical yield, others were incompatible under the experimental conditions used.
Highlights
In a Fall 1974 invited lecture before the Pittsburgh Section of the ACS, Professor SamuelDanishefsky stated, reporting on his group’s progress toward a synthesis of vernolepin, that: “A synthesis cannot be considered truly elegant if it does not contain at least one Diels-Alder reaction.” The transformations being cited are shown in Scheme 1 and are discussed in [1].Scheme 1
This is unfortunate for the student who wants to learn about synthesis
This review summarizes our exploration of the Diels-Alder reactions of 12-hydroxy-9(10→20)5aH-abeo-abieta-1(10),8(9),12(13)-triene-11,14-dione, which will be referred to as quinone 2 or quinone (S)-2, for the synthesis of perovskone and related natural products
Summary
In a Fall 1974 invited lecture before the Pittsburgh Section of the ACS, Professor Samuel. The more sequential transformations that can occur, the fewer the steps needed to achieve a given total synthesis, and the more efficient the synthesis is. Such transformations have been widely studied and are described in the literature either as a cascade, [33] domino, [34] tandem, [35] consecutive, [36] or as an one-pot reaction. In 1994 we achieved a 16-step synthesis of the triterpene (±)-perovskone (1) [37] that featured a cascade process in which three rings and five stereocenters of the product were created in a single operation (Scheme 2) [38].
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
