TY - JOUR
T1 - Biomimetic syntheses of ineleganolide and sinulochmodin C from 5-episinuleptolide via sequences of transannular Michael reactions
AU - Li, Yi
AU - Pattenden, Gerald
N1 - Funding Information:
We are grateful to Professor J.-H. Sheu (National Sun Yat-sen University, Taiwan) for his kindness in providing samples of naturally derived 5-episinuleptolide and ineleganolide, used in these studies. We also thank the University of Nottingham for financial support.
PY - 2011/12/23
Y1 - 2011/12/23
N2 - Treatment of a solution of the macrocyclic norcembranoid 7 with lithium hexamethyldisilazide in THF at -78 °C to 0 °C, leads to the polycyclic norcembranoids ineleganolide 1 and sinulochmodin C (2) (65%), which are found in the corals Sinularia inelegans and Sinularia lochmodes, respectively. The conversions are believed to be biomimetic, and occur by successive transannular Michael reactions in 7. Under different temperature conditions the novel polycycle 30 is the main product, alongside small quantities of 1 and 2. The polycycle 30 is possibly produced from ineleganolide 1, following a reverse oxy-Michael reaction and two successive aldol reactions. The significance of the synthesis of ineleganolide 1, sinulochmodin C (2) and the structure 30 from 5-episinuleptolide 7, to the likely biosynthesis of the related norcembranoids scabrolide A (3), scabrolide B (4) and horiolide 31 found in Sinularia sp. is discussed.
AB - Treatment of a solution of the macrocyclic norcembranoid 7 with lithium hexamethyldisilazide in THF at -78 °C to 0 °C, leads to the polycyclic norcembranoids ineleganolide 1 and sinulochmodin C (2) (65%), which are found in the corals Sinularia inelegans and Sinularia lochmodes, respectively. The conversions are believed to be biomimetic, and occur by successive transannular Michael reactions in 7. Under different temperature conditions the novel polycycle 30 is the main product, alongside small quantities of 1 and 2. The polycycle 30 is possibly produced from ineleganolide 1, following a reverse oxy-Michael reaction and two successive aldol reactions. The significance of the synthesis of ineleganolide 1, sinulochmodin C (2) and the structure 30 from 5-episinuleptolide 7, to the likely biosynthesis of the related norcembranoids scabrolide A (3), scabrolide B (4) and horiolide 31 found in Sinularia sp. is discussed.
KW - Biomimetic synthesis
KW - Ineleganolide
KW - Norcembranoid
KW - Sinulochmodin C
KW - Transannular cyclisation
UR - http://www.scopus.com/inward/record.url?scp=81255208512&partnerID=8YFLogxK
U2 - 10.1016/j.tet.2011.09.040
DO - 10.1016/j.tet.2011.09.040
M3 - Article
AN - SCOPUS:81255208512
SN - 0040-4020
VL - 67
SP - 10045
EP - 10052
JO - Tetrahedron
JF - Tetrahedron
IS - 51
ER -