D. A. Evans Polypropionate Biosynthesis: A Laboratory Simulation Chem 206 Polypropionate Polyacetate Biosynthesis Develop a Laboratory Simulation Latter Stages of Lonomycin Biosynthesis OMe Me MeMeMeMeMeMe Me Erythrolide B The 7 Propionate Subunits HO2C Polypropionate Biosynthesis: The Elementary Steps 义人 MeMeMeMe Me Me me Cane. C Acylation 人 Reduction R Sn(oTf)2 EtN(Pr2 The Laboratory Mimic. 95:5(685%yed) Dipropionyl Synthon ee Lecture 23; page 23-08 Me ome with M. Ennis JACS 1984. 106. 1154 937(86%yed with Ratz, Huff, Sheppard, JACS 1995, 117, 3448O N Me O O Me O Bn N O Me O O Me O Bn O HO Me SR O O Me OH R SR O R SR OR Me O Me Et O O Me OH OR Me Me Me H OH R SR O Me O R O Me O Me OH SR Me OH OH Me OH Me O Me Me HO OH Me OH Me O O Me OH Me OH Me Me O Me OH Me OH OH Me R SR OH Me O SR OH Me OH Me O R Sn(OTf)2 HO2C OMe Me O Me Me OH Me OH Me OMe O Me Me Me Me OMe Me OMe Me O O HO2C O Me OMe Me Me OMe Me OH Me O O Me Me O O Me OMe Me OMe Me Me OH H H H OH O Me Me O Me O OMe Me Me O Me OMe O HO2C O Me OMe Me Me OMe Me OH Me H XC O Me O Me R H O O O Me OMe R–CHO TiCl4 N O O Me O Bn OH Me R O O Me Me O O Bn O N O Me O D. A. Evans Polypropionate Biosynthesis: A Laboratory Simulation Chem 206 ✻ ✻ ✻ ✻ ✻ – CO2 Acylation Reduction Polypropionate Biosynthesis: The Elementary Steps Acylation – CO2 Erythrolide B The 7 Propionate Subunits Polypropionate & Polyacetate Biosynthesis: Develop a Laboratory Simulation ? The Laboratory Mimic: Aldol (–) Cane, Celmer, Westley JACS 1983, 105, 3594 Reduction Latter Stages of Lonomycin Biosynthesis 95:5 (85% yield) EtN(iPr)2 93:7 (86% yield) EtN(iPr)2 with Ratz, Huff, & Sheppard, JACS 1995, 117, 3448 See Lecture 23; page 23-08: with M. Ennis JACS 1984, 106, 1154. Dipropionyl Synthon