Enantioselective total synthesis of (+)-labd-8(17)-ene-3β,15-diol and (−)-labd-8(17)-ene-3β,7α,15-triol
摘要:
Enantioselective total synthesis of the labdane diterpenes (+)-labd-8(17)-ene-3 beta,15-diol ((+)-1) and (-)-labd-8(17)-ene-3 beta,7 alpha, 15-triol ((-)-2) was achieved starting from the (S)-(+)-enantiomer of the Wieland-Miescher ketone (+)-3 and the (R)-(+)-enantiomer of lactone (+)-13. These results established that the natural compounds (+)-1 and (-)-2 possess the (13S) absolute configuration. (C) 1997 Published by Elsevier Science Ltd.
An enantioselective synthesis of the tetracyclic ABCD ring system (4) of kampanols, novel Ras farnesyltransferase inhibitors from a microorganism, was efficiently achieved for the first time starting from the known trans-decalone derivative 9. The synthetic method involves the following two key steps: (i) a conjugate addition reaction between the α-methylene ketone 6 and the Grignard reagent (7) of