A mixture of the methyl esters of communic acids (3b, 4b, 5b) was used in the synthesis of the ambergris-type odorants Ambrox(R) (1) and ambracetal (2). Both syntheses involve methyl ketone 7 as the key intermediate.
摘要 (8 R ,13 S )-8α,13:13,17-diepoxy-14,15-dinorlabdane-19-oate 易于从交流酸中制备,是合成五环类类化合物的合适中间体,因为它可以制备这些萜类化合物的 A 环和 B-C-D 环系统的进一步构建。在消除酯基和在 C-3 上引入羟基期间所用的反应条件下,缩醛基团是稳定的。同时,它能够再生甲基13-oxo-14,15-dinorlabd-8(17)en-19-oate所呈现的甲基酮和环外双键。后一种化合物以前被用于构建这些类类化合物的 B-C-D 环。
Enantiospecific synthesis of antifungal dasyscyphin E from cupressic acid
作者:Antonio Fernández、Ettahir Boulifa、Fermín Jiménez、Soumicha Mahdjour、Ahmed I. Mansour、Rachid Chahboun、Enrique Alvarez-Manzaneda
DOI:10.1016/j.tet.2017.09.048
日期:2017.11
The first synthesis of the sesquiterpene quinol dasyscyphin E has been achieved starting from cupressic acid. Key steps of the synthetic sequence are the oxidative degradation of the diterpene side chain to give a methylketone, the diastereoselective α-methylation of a protected ketoaldehyde, the subsequent intramolecular aldol condensation and the further Diels-Aldercycloaddition of a dienol ester