A.I. Scott

The structure and chemistry of hirsutic acid

Abstract By a necessary combination of chemical and X-ray studies the structure and stereochemistry of the sesquiterpenoid acid, hirsutic acid C (C 15 H 20 O 4 ) from Stereum hirsutum have been established as shown in I. An unusual rearrangement involving solid state X-irradiation has been discovered and evaluated.

Biogenetic-type synthesis of the Calycanthaceous alkaloids.

Abstract Oxidative dimerization of N b -methyltryptamine occurs exclusively via ββ-coupling in a one-step synthesis of rac - and meso -chimonanthine. Transformation of the former to rac -calycanthine completes a synthesis of all the dimeric alkaloids of Calycanthus species. The structure of some minor by-products of this oxidation are discussed.

Pyrone studies—II

Abstract Further studies on the use of pyrones for the biogenetic-type synthesis of phenolic compounds are reported. In particular some control over the direction of cyclization of the intermediate β-triketo ester chain is demonstrated. This control makes possible the synthesis of two basic types of phenolic compound from the same precursor and is analogous to the probable biosynthesis of these compounds in the natural system.

Total synthesis of colchicine modelled on a biogenetic theory.

Abstract A five step synthesis of desacetamidocolchiceine (XLVI) is described in which rings A and C are joined by oxidative coupling of the tropolone system. This completes a biogenetic-type total synthesis of colchicine (I).