Laboratory emulation of polyketide biosynthesis: an iterative, aldol-based, synthetic entry to polyketide libraries using (R)- and (S )-1-(benzyloxy)-2-methylpentan-3-one, and conformational aspects of extended polypropionates
Laboratory emulation of polyketide biosynthesis: an iterative, aldol-based, synthetic entry to polyketide libraries using (R)- and (S )-1-(benzyloxy)-2-methylpentan-3-one, and conformational aspects of extended polypropionates
Polyketide library synthesis: Iterative assembly of extended polypropionates using (R)- and (S)-1-(benzyloxy)-2-methylpentan-3-one
作者:Ian Paterson、Jeremy P. Scott
DOI:10.1016/s0040-4039(97)01751-6
日期:1997.10
The heptapropionates 5 and 20 were synthesised by iterative application of the boron-mediated aldol reaction of ethyl ketone (R)-4 and subsequent reduction. Polyketide library diversification was realised by varying the ketone configuration and substitution in the aldol bond constructions. (C) 1997 Elsevier Science Ltd.
Laboratory emulation of polyketide biosynthesis: an iterative, aldol-based, synthetic entry to polyketide libraries using (R)- and (S )-1-(benzyloxy)-2-methylpentan-3-one, and conformational aspects of extended polypropionates
作者:Ian Paterson、Jeremy P. Scott
DOI:10.1039/a809818b
日期:——
Iterative, one-directional, boron-mediated aldol chain extensions, using the dipropionyl reagent (R)-1-(benzyloxy)-2-methylpentan-3-one 7, have enabled the highly diastereoselective assembly of the stereoregular heptapropionates 5 and 6. The synthetic sequence developed permits structural diversity through variation in the stereochemical nature of the aldolisation and reduction steps, together with the choice of the chiral ketone employed at each iteration. The heptapropionate 5 has been shown to represent an example of a fully flexible molecule, whose backbone nevertheless adopts a single preferred conformation. It forms part of a family of conformationally controlled polyols, exploiting the avoidance of syn-pentane interactions and the preference for preorganisation through intramolecular hydrogen bonding.