A nine-step, stereoselective synthesis of bipinnatin J is described, which features a ruthenium-catalyzed Alder-ene reaction, a Stille cross coupling, and an intramolecular Nozaki-Hiyama-Kishi allylation as key steps. The biosynthetic relationship between bipinnatin J and complex polycyclic diterpenes isolated from gorgonian corals is discussed.
Stereoselective Synthesis of β-(Hydroxymethylaryl/alkyl)-α-methylene-γ-butyrolactones
作者:David M. Hodgson、Eric P. A. Talbot、Barry P. Clark
DOI:10.1021/ol200711f
日期:2011.5.20
Zinc or a chromium(II) source with 3-(bromomethyl)furan-2(5H)-one (3) and an aldehyde gives beta-(hydroxymethylaryl/alkyl)-alpha-methylene-gamma-butyrolactones 5 in good yields and high diastereoselectivities. The methodology is demonstrated in concise syntheses of (+/-)-hydroxymatalresinol (8) and (+/-)-methylenolactocin (10) by subsequent arylboronate conjugate addition and translactonization, respectively.
Total synthesis of (+)-Z-deoxypukalide, a furanobutenolide-based cembranoid isolated from the pacific octocoral Leptogorgia spp.
作者:Bencan Tang、Christopher D. Bray、Gerald Pattenden、Joseph Rogers
DOI:10.1016/j.tet.2010.01.059
日期:2010.3
A total synthesis of (+)-Z-deoxypukalide 3 using a combination of Stille and Nozaki-Hiyama-Kishi(NHK) coupling reactions as key steps, is described. During this study a new practical synthesis of the substituted butenolide intermediate 10, based on a combination of RCM and CM reactions from the cyclobutene ester 21 in the presence of 2-methylpropenol was also developed. Attempts to apply the intramolecular NHK reaction to the substrates 8a and 8b containing an ester group adjacent to the reacting aldehyde functionality gave disappointing low yields (<6%) of the corresponding coupled products 9. The synthetic (+)-Z-deoxypukalide 3 was correlated with naturally derived material, and also with pukalide 1, the first member of the furanobutenolide-based cembranoids to be isolated from corals. (C) 2010 Elsevier Ltd. All rights reserved.