39012-00-5Relevant articles and documents
A facile total synthesis of (±)-cembrene by titanium-induced keto ester cyclization
Li,Li,Li
, p. 678 - 680 (1994)
A direct approach of titanium-induced intramolecular keto ester cyclization was applied to the total synthesis of macrocyclic diterpenoids, by which (±)-cembrene was synthesized from geranylacetone by a short and efficient route.
Facile and Practical Total Syntheses of (+/-)-Mukulol and (+/-)-Cembrene by Low-valent Titanium-induced Keto Ester Cyclization
LI, Weidong,LI, Ying,LI, Yulin
, p. 741 - 744 (2007/10/02)
A direct approach of low-valent titanium-induced intramolecular keto ester cyclization was first applied to the total syntheses of macrocyclic diterpenoids, by which (+/-)-mukulol and (+/-)-cembrene were synthesized from geranylacetone by a short and efficient route.
Synthesis of Macrocyclic Propargylic Alcohols by Ene-Type Cyclization of Unsaturated Acetylenic Aldehydes
Marshall, James A.,Andersen, Marc W.
, p. 2766 - 2768 (2007/10/02)
Ene type cyclizations of ynals 6, 21, and 30 can be effected by EtAlCl2 in CH2Cl2 at -78 deg C to afford 14- and 12-membered homoallylic propargylic alcohols in 66-89 percent yield.
Macrocyclisations using Allylic Radical Intermediates. A New Synthetic Approach to Natural 14-Membered Cembranoids
Cox, Nicolas J. G.,Mills, Stuart D.,Pattenden, Gerald
, p. 1313 - 1322 (2007/10/02)
A range of alternative radical macrocyclisation approaches to cembranoids have been evaluated.Radical macrocyclisations involving the allylic radicals 11 generated from the corresponding allylic iodides, 15b and 20b, in the presence of Bu3SnH-AIBN, are shown to lead to 14-membered trienones, viz 10, via selective 14-endo-trig processes.Both 10a and 10b can then be elaborated to the natural marine cembranoids 8 (mukulol) and 9 respectively, by straightforward functional group interconversions.Concise syntheses of the α,ω-dial 28, the terminal acetylenic aldehyde 27 and the allylic iodide enal 37 were developed, but neither was found to undergo radical mediated cyclisation to the corresponding 14-membered carbocycles 29, 30 and 38 respectively.Instead, only the products of reduction, e.g. 39, or intermolecular pinacolisation, e.g. 34 were produced.
RADICAL MACROCYCLISATIONS IN SYNTHESIS. A NEW APPROACH TO MUKULOL AND MARINE CEMBRANOLIDE LACTONES
Cox, Nicholas J. G.,Pattenden, Gerald
, p. 621 - 624 (2007/10/02)
Radical macrocyclisations, involving the allylic dienones (11b) and (16), are shown to lead to 14-membered precursors, i.e. (12) and (18), for the synthesis of the marine cembranolide lactone (6) and mukulol (5) respectively.
