Synthesis of (?)-Pinidinevia asymmetric, electrophilic enolate hydroxyamination/nitrone reduction
作者:Wolfgang Oppolzer、Eric Merifield
DOI:10.1002/hlca.19930760218
日期:1993.3.24
Enantiomerically pure(−)-pinidine (1) has been synthesized in 18.5% overall yield by a nine-step sequence starting from keto-ester 2. The key step 5 6 involves an asymmetric, electrophilicenolatehydroxyamination. Diastereoselective hydrogenation of nirtone 6 ensures the cis-relation between the substituents at C(2) and C(6) in piperidine 7.
Under acidic conditions zinc reduces diselenides to afford selenols, which can be either isolated or treated in situ with alkyl halides to produce alkyl selenides or with epoxides to give β-hydroxyselenides.
Cyclofunctionalisation of epoxyalcohol derivatives. 4. Cyclisation of sulfonylacetate dianions: A synthesis of “MeBMT”
作者:Stuart W. McCombie、Bandarpalle B. Shankar、Ashit K. Ganguly
DOI:10.1016/s0040-4039(01)93415-x
日期:——
α,α-Dianions, derived from arenesulfonylacetate esters of 2,3-epoxyalcohols, cyclised to give 3-arenesulfonyl-4-(1-hydroxyalkyl)-γ-butyrolactones. Dianion fragmentation to regenerate the epoxyalcohol was a competing, substrate-dependent process. Sulfonyllactone (9) was elaborated efficiently to an advanced intermediate for the unusual aminoacid “MeBMT” (5), and also to stereodefined cyclopropane derivatives
The Total Synthesis of Corallopyronin A and Myxopyronin B
作者:Andreas Rentsch、Markus Kalesse
DOI:10.1002/anie.201206560
日期:2012.11.5
Leading the way: The synthesis of natural products with new biological targets is one of the driving forces for the development of new antibiotics. The synthesis of the two secondary metabolites corallopyronin and myxopyronin (see picture) have been achieved, which are prominent leads for the inhibition of bacterial RNA polymerase.