Synthesis of β-hydroxy-δ-trichloromethyl-δ-valerolactones by intramolecular samarium/ytterbium diiodide-mediated Reformatsky reaction

Cross-Coupling Reactions Using Samarium(II) Iodide

“…Treatment of the ketone precursor with SmI 2 –THF at −78 °C gave bicyclic lactone in modest yield. In 2013, Schultz reported the use of an intramolecular SmI 2 -mediated Reformatsky reaction to prepare δ-trichloromethyl-δ-valerolactones in modest yields and good diastereoselectivity (not shown) …”

“…In 2013, Schultz reported the use of an intramolecular SmI 2 -mediated Reformatsky reaction to prepare δ-trichloromethyl-δ-valerolactones in modest yields and good diastereoselectivity (not shown). 482 The SmI 2 -promoted intramolecular Reformatsky reaction has been used for the synthesis of nucleosides and amino acid derivatives (Schemes 224 and 225). 483,484 In 2006, Ischikawa and Matsuda reported the intramolecular Reformatsky reaction as the key step to introduce a carbon substituent at the 3-position in the synthesis of 3′-β-carbamoylmethylcytidine, a branched-chain nucleoside with potent antitumor activity (Scheme 224).…”

Recent developments in the asymmetric Reformatsky-type reaction

“…The same year, Schulze et al reported the synthesis of chiral β-hydroxy-α-methyl-δ-trichloromethyl-δ-valerolactone ( 39 ) through a diastereoselective Sm(II)- or Yb(II)-mediated Reformatsky reaction of the corresponding aldehyde 40 [ 33 ]. Starting from a diastereomerically enriched aldehyde 40 (82% de), the reaction performed in THF at −40 °C in the presence of 3 equivalents of SmI 2 or YbI 2 provided the corresponding chiral lactone 39 as major diastereomer (58% de) in moderate yield (29 and 30%, respectively), as shown in Scheme 16 .…”

“… Synthesis of β-hydroxy-α-methyl-δ-trichloromethyl-δ-valerolactone through a Sm(II)- or Yb(II)-mediated Reformatsky reaction [ 33 ]. …”