Enantio-complementary total asymmetric syntheses of prostaglandin E2 and prostaglandin F2?
作者:John Davies、Stanley M. Roberts、Derek P. Reynolds、Roger F. Newton
DOI:10.1039/p19810001317
日期:——
bromohydrins (–)-(9) and (+)-(9). The bromohydrin (–)-(9) was converted into prostaglandinE2(1) and prostaglandin F2α(2) by reaction of the chiral cuprate reagent (15) with the tricyclic ketone (10), while the bromohydrin (+)-(9) was converted into the prostaglandins by reaction of the epoxyacetal (11) with the same cuprate reagent (15).
tested in the microbial reduction of methyl-substituted bicyclo[3.2.0]hept-3-en-6-ones 1a-c. The endo-alcohols 2a-c were obtained with good yields and enantiomeric excess. Lower yields are described for the exo-alcohols 3a-c which are normally enantiomerically pure. Comparisons with microbial reduction of bicyclo[3.2.0]hept-2-en-6-one 1d and bicyclo[3.3.0]oct-7-en-2-one 1e are also reported.
The reduction of 5-hexen-2-one 1, 6-methyl-5-hepten-2-one 2, acetophenone 3, cis-bicyclo[3.2.0]hept-2-en-6-one 4 and 2-methylcyclohexanone 5 with various commercially available plants (i.e., Brassica oleracea botrytis, Cucurbita maxima, Cucurbita pepo, Cynara scolimus, Daucus carota, Foeniculum vulgare and Musa sapientum) is reported. In the reduction of ketones 1-3, both (S)- and (R)-enantiomers 6-8 were obtained in good yields and with appreciable enantiomeric excesses. With racemic ketones 4 and 5, both the diastereomeric endo/exo 9 and 10 and cis/trans 11 and 12 are produced with variable yields and enantiomeric excesses depending on the various plants used. (c) 2006 Elsevier Ltd. All rights reserved.