69940-49-4Relevant articles and documents
PIMARANE AND CLEISTANTHANE DITERPENES FROM VELLOZIACEAE: ABSOLUTE CONFIGURATION AND BIOMIMETIC CONVERSION
Pinto, A. C.,Patitucci, M.L.,Silva, R.S. Da,Queiroz, P.P.S.,Kelecom, A.
, p. 3351 - 3354 (1983)
Pimarane and cleistanthane diterpenes isolated from Velloziaceae are shown, by CD studies, to possess the same (5S,10S) absolute configuration.A biomimetic rearrangement of the pimarane into the cleistanthane skeleton is described.The structure of a new natural diterpene, cleistantha-8,11,13-trien-7-one is also reported.
Birch reduction of 14-methoxypodocarpa-8,11,13-triene and a stereoselective synthesis of veadeiroic acid and veadeirol - Two novel diterpenes with cleistanthane skeleton
Saha, Arabinda,Mahapatra, Bimal,Nasipuri, Dhanonjoy
, p. 721 - 722 (2007/10/02)
14-Methoxypodocarpa-8,11,13-triene (1) has been reduced by Li in liquid NH3, using EtOH-t-BuOH with THF as cosolvent to 14-oxopodocarpa-8(9)-ene (5) as the major product.This is converted successively into a keto-acetal (6), a dihydrobenzaldehyde (8), and an aromatic aldehyde (9) through more or less standard reactions.The aldehyde (9) is oxidised to (+/-)-veadeiroic acid (2a) and reduced to (+/-)-veadeirol (2b) thus effecting the first total synthesis of these two naturally occurring diterpenes with rare cleistanthane skeleton.