Komppa G.
University of Helsinki, Finland
Die vollständige Synthese der Camphersäure und Dehydrocamphersäure.
Ber. Dtsch. Chem. Ges. 1903;
36: 4332-4335
DOI:
10.1002/cber.190303604115
Key words
camphor - Wagner–Meerwein rearrangement - non-classical carbocation
Significance
Camphor is a common terpene building block in natural product synthesis. Notably, the synthesis of Taxol by the Holton group commences with camphor. Komppa’s pioneering synthesis set the standard for the future industrial route starting from α-pinene and taking advantage of sequential Wagner–Meerwein rearrangements and non-classical cations to enable rapid access to camphor.
Comment
Komppa’s camphor synthesis begins with a double Claisen condensation, a diol reduction, and a red phosphorous-mediated elimination. From there, camphoric acid and campholide are prepared which lead to an interesting Ca(OH)2-promoted decarboxylative Dieckmann condensation, presumably through a calcium chelate.
