Table 1. Variations of the ester moiety
graphic
Entry R d.r.* Yield, %
1 Me 50:50 90 graphic
2 i-Pr 63:37 91
3 Benzhydryl 64:36 85
4 tert-Bu (5) 80:20 90
5 Neopentyl 82:18 85
6 MCP (6) 89:11 87
7 CP 54:46 90 L = TMSCI or THF, M = TMS or Li+
  • OBOM or BOMO, O-benzyloxymethyl; TMSCI, chlorotrimethysilane; TBDPS, tert-butyldiphenylsilyl; CP, cyclopentyl.

  • * Diastereomeric ratio determined by inverse-gated homodecoupling 13C NMR