89726-87-4Relevant articles and documents
Total synthesis of depsilairdin
Ward, Dale E.,Pardeshi, Sandip G.
supporting information; scheme or table, p. 5170 - 5177 (2010/09/16)
(Figure presented) The total synthesis of depsilairdin, a host-selective phytotoxin isolated from Leptosphaeria maculans (the causal agent of blackleg disease of oilseed Brassicas), has been achieved by N-terminal extension of a suitably protected derivative of the hitherto unknown amino acid (2S,3S,4R)-3,4-dihydroxy-3-methyl-proline (Dhmp) followed by esterification with lairdinol A. The latter esterification, complicated by the sterically hindered nature of the carboxyl group, was accomplished by a novel method involving reaction of the 1-hydroxybenzotriazole (HOBt) derived active ester with the bromomagnesium alkoxide of lairdinol A. Three depsilairdin analogues were also prepared by replacing the Dhmp residue with l-proline and cis- and trans-4-hydroxy-l-proline. Phytotoxicity assays showed that the analogues were nontoxic to both blackleg-susceptible (brown mustard) and -resistant (canola) plants, suggesting that the presence of the Dhmp residue in depsilairdin is important for its host-selective toxicity toward brown mustard.
MILD CLEAVAGE OF METHOXYMETHYL (MOM) ESTERS WITH TRIMETHYLSILYLBROMIDE
Hanessian, Stephen,Delorme, Daniel,Dufresne, Yves
, p. 2515 - 2518 (2007/10/02)
Trimethylsilyl bromide is an effective reagent for the deprotection of methoxymethyl ethers under mild conditions.
