319475-28-0Relevant academic research and scientific papers
Synthesis of butenolides recently isolated from marine microorganisms
Karlsson, Staffan,Andersson, Fredrik,Breistein, Palle,Hedenstr?m, Erik
, p. 7878 - 7881 (2008/03/11)
The syntheses and 13C NMR analyses of four diastereomeric butenolides, two of which were recently isolated from the marine microorganisms Streptomycete B 5632 and Streptoverticillium luteoverticillatum 11014 are described. The two isolated butenolides were found to be one of the two diastereomers (4S,10R*,11R*)-4,11-dihydroxy-10-methyl-dodec-2-en-1,4-olide (RRS-1 or SSS-1) and one of the two diastereomers (4S,10S*,11R*)-4,11-dihydroxy-10-methyl-dodec-2-en-1,4-olide (SRS-1 or RSS-1). An asymmetric 1,3-dipolar cycloaddition of a thiocarbonyl ylide with a dipolarophile attached to camphorsultam and a ring-opening of an enantiomerically pure vinyloxirane by lithiated dithiane served as key steps for the construction of the three stereogenic centres. Further elaborations including ring-closing metathesis and Mitsunobu inversion furnished the four diastereomeric butenolides.
Pheromones of pine sawflies: Synthesis of a pure (2S,3R)-3-methylalkan-2-ol stereoisomer via an asymmetric 1,3-dipolar cycloaddition; preparation of a pheromone component of Macrodiprion nemoralis
Karlsson,Hoegberg
, p. 1863 - 1867 (2007/10/03)
This paper presents a new approach to the preparation of enantiomerically pure (2S,3R)-3-methylalkan-2-ols, the esters of which are sex pheromones of several pine sawflies. Thus, an asymmetric 1,3-dipolar cycloaddition between a sulfur containing 1,3-dipole and a dipolarophile attached to (1R)-camphorsultam containing a vinyl ether functionality furnished a 90:10 diastereomeric mixture of trans-3,4-disubstituted tetrahydrothiophene amides. The major one was converted to an enantiomerically pure tetrahydrothienylmethyl bromide, which was coupled with a monoalkylated dithiane unit. After Raney nickel reduction (2S,3R,7R,9S)-3,7,9-trimethyltridecan-2-ol was obtained, the acetate of which is the attractant sex pheromone component of Macrodiprion nemoralis. Because this new approach is quite efficient it can be valuable for the synthesis of similar compounds.
