Biogenetic-Type Total Synthesis of (±)-2-Deoxystemodinone. Preliminary Communication
作者:Alessandro Lupi、Maria Patamia、Ingeborg Grgurina、Rinaldo Marini Bettolo、Ornella Di Leo、Patrizia Gioia、Simonetta Autnaroli
DOI:10.1002/hlca.19840670832
日期:1984.12.19
A biogenetic-typetotalsynthesis of(±)-2-deoxystemodinone (1), by solvolytic rearrangement of the 1-methyl[2.2.2]oct-2-yl methanesulphonate 4, is described.
Investigation of the importance of the C-2 oxygen function in the transformation of stemodin analogues by Rhizopus oryzae ATCC 11145
作者:Glenroy D.A. Martin、William F. Reynolds、Paul B. Reese
DOI:10.1016/j.phytochem.2004.01.011
日期:2004.3
A new stemodinoside, stemodin-a-L-arabinofuranoside (5), was isolated from the plant Stemodia maritima. Incubation of stemodin (2) with Rhizopus oryzae ATCC 11145 gave 2alpha,7beta,13(S)-trihydroxystemodane (17) and 2alpha,3beta,13(S),16alpha-tetrahydroxystemodane (18) whilst stemodinone (8) afforded 6alpha,13(S)-dihydroxystemodan-2-one (19). The bioconversion of 2beta,13(S)-dihydroxystemodane (10) by the fungus yielded 2beta,7beta,13(S)-trihydroxystemodane (20) whereas stemod-12-en-2-one (9) provided 7beta,17-dihydroxystemod-12-en-2-one (21). The results provide useful information about the relationship between the functional groups of the substrates and their potential for bioconversion. (C) 2004 Elsevier Ltd. All rights reserved.
Construction of the Stemodane Nucleus by a Hydroxyl-Directed Intramolecular Ene Reaction. Total Synthesis of (.+-.)-2-Desoxystemodinone
作者:James D. White、Todd C. Somers
DOI:10.1021/ja00101a012
日期:1994.11
A synthesis of the diterpene 2-desoxystemodinone was completed from the known tricyclic ketone 9 in eight steps and 35% overall yield. The key step involved a thermal intramolecular ene reaction of alpha-hydroxy aldehyde 21 which led to 24 in 94% yield. By contrast, a Lewis acid-catalyzed ene reaction of 21 gave oxetane 25 as the major product. The pivotal role of the hydroxyl substituent of 21 in facilitating the ene reaction was demonstrated and is rationalized by a hydrogen bond which orients the carbonyl in a favorable conformation for rearrangement.
Total synthesis of (.+-.)-2-desoxystemodinone. A novel hydroxyl-assisted, intramolecular ene reaction