Enantioselective total synthesis of (+)-leucascandrolide A macrolactone.
نویسندگان
چکیده
[reaction: see text] The enantioselective synthesis of the (+)-leucascandrolide A macrolactone has been achieved in 20 linear steps from 1,3-propanediol. The key steps in the synthesis are a reductive cleavage of bicyclic ketal 5 to establish the C15 stereogenic center and a diastereoselective aldol of the boron enolate of methyl ketone 3 to aldehyde 4 in preparation for a heteroconjugate addition for the introduction of the C3 stereocenter.
منابع مشابه
Enantioselective total synthesis of callipeltoside A: two approaches to the macrolactone fragment.
The enantioselective total synthesis of callipeltoside A is described. Two syntheses of the macrolactone subunit are included: the first relies upon an Ireland-Claisen rearrangement to generate the trisubstituted olefin geometry and the second utilizes an enantioselective vinylogous aldol reaction for this purpose. Enantioselective syntheses of the sugar and chlorocyclopropane side chain fragme...
متن کاملAryne acyl-alkylation in the general and convergent synthesis of benzannulated macrolactone natural products: an enantioselective synthesis of (-)-curvularin.
A general approach for the synthesis of benzannulated macrolactone natural products utilizing an aryne acyl-alkylation reaction is described. Toward this end, the total syntheses of the natural products (-)-curvularin, curvulin, and (-)-diplodialide C are reported. Furthermore, the aryne insertion technology has enabled the rapid conversion of simple diplodialide natural products to curvularin,...
متن کاملTotal Synthesis of (+)-18-epi-Latrunculol A: Development of a Synthetic Route
The evolution of an enantioselective total synthesis of (+)-18-epi-latrunculol A, a congener of the marine-sponge-derived latrunculins A and B, is reported. Key steps include a late-stage Mitsunobu macrolactonization to construct the 16-membered macrolactone, a mild Carreira alkynylation to unite the northern and southern hemispheres, a diastereoselective, acid-mediated δ-hydroxy enone cyclizat...
متن کاملRegio‐ and Stereoselective Homologation of 1,2‐Bis(Boronic Esters): Stereocontrolled Synthesis of 1,3‐Diols and Sch 725674
1,2-Bis(boronic esters), derived from the enantioselective diboration of terminal alkenes, can be selectively homologated at the primary boronic ester by using enantioenriched primary/secondary lithiated carbamates or benzoates to give 1,3-bis(boronic esters), which can be subsequently oxidized to the corresponding secondary-secondary and secondary-tertiary 1,3-diols with full stereocontrol. Th...
متن کاملSynthesis of the C1-C13 fragment of leucascandrolide A.
[reaction: see text] The synthesis of the C1-C13 fragment 3 of leucascandrolide A has been completed utilizing a stereoselective and regioselective reductive cleavage of a highly functionalized spiroketal to incorporate the cis-2,6-disubstituted tetrahydropyan. The spiroketal was constructed by addition of a lithiated pyrone 5 to aldehyde 6.
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Organic letters
دوره 5 24 شماره
صفحات -
تاریخ انتشار 2003