The total synthesis of both oridamycin A and oridamycin B was accomplished starting from a common synthetic intermediate readily prepared from geranyl acetate. The sequence utilizes an oxidative radical cyclization to construct the trans-decalin ring system, setting three of four contiguous stereocenters in one operation. The carbazole nucleus was forged through a one-pot process entailing acid-promoted dehydration followed by 6 pi-electrocyclization/aromatization.
Synthesis of the Dolabellane Diterpene Hydrocarbon (�)-?-araneosene
作者:Luzi Jenny、Hans-J�rg Borschberg
DOI:10.1002/hlca.19950780318
日期:1995.5.10
bicyclic diterpenehydrocarbon δ-araneosene (4), endowed with the dolabellane skeleton, was prepared from geraniol in two different ways. The more efficient route involved 13 steps and proceeded with an overall yield of 3.6% (average: 77% per step). With this reference sample at hand, the hitherto elusive metabolite (−)-4, a likely biogenetic precursor of cycloaraneosene ((−)-3) and sordaricin ((−)-1),