Dolasta-1 ,7,9-trien synthesis

The enantioselective ex-chiral-pool synthesis of the enantiomer of the natural (-i-)-dolasta-l(15),7,9-trien-14-ol (ent-122) was achieved by Mehta and coworkers in 1987 (Scheme 24) [85, 86]. From the hydroazulene 136, the synthesis proceeded analogous to the synthesis of Pattenden (Scheme 20) and provided the dolastane ent-122 as a mixture with the non-natural dolas-tanes 153 and 154. However, in contrast to Pattenden s work, Mehta and... 

Scheme 24 Synthesis of (-l-)-dolasta-l(15),7,9-trien-14-ol (ent-122) achieved by Mehta (1987)...

Piers, E. and Friesen, R.W. (1992) Annulations leading to diene systems. Total synthesis of the dolastane-type diterpenoids ( )-(5S,12R,14S)-dolasta-l(15),7,9-trien-14-ol and ( )-amijitrienol. Can.J. Chem., 70, 1204-1220. 

Pattenden, G. and Robertson, G.M. (1986) Free radical reactions in synthesis. Total synthesis of isoamijiol. Tetrahedron Lett., 27,399-402. Mehta, G. and Krishnamurthy, N. (1987) An enantioselective approach to dolastane diterpenes. Total synthesis of marine natural products (+)-isoamijiol and (+)-dolasta-l(15),7,9-trien-14-ol. Tetrahedron Lett., 28, 5945-5948. 

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