319475-24-6Relevant articles and documents
Synthesis of butenolides recently isolated from marine microorganisms
Karlsson, Staffan,Andersson, Fredrik,Breistein, Palle,Hedenstr?m, Erik
, p. 7878 - 7881 (2007)
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.